Use <see langword="*"/> instead of <c>*</c>

shared/OpenIddict.Extensions/Helpers/OpenIddictHelpers.cs

@@ -10,7 +10,7 @@ internal static class OpenIddictHelpers
     /// </summary>
     /// <param name="type">The type to introspect.</param>
     /// <param name="definition">The generic type definition.</param>
-    /// <returns>A <see cref="Type"/> instance if the base type was found, <c>null</c> otherwise.</returns>
+    /// <returns>A <see cref="Type"/> instance if the base type was found, <see langword="null"/> otherwise.</returns>
     public static Type? FindGenericBaseType(Type type, Type definition)
         => FindGenericBaseTypes(type, definition).FirstOrDefault();
 
@@ -19,7 +19,7 @@ internal static class OpenIddictHelpers
     /// </summary>
     /// <param name="type">The type to introspect.</param>
     /// <param name="definition">The generic type definition.</param>
-    /// <returns>A <see cref="Type"/> instance if the base type was found, <c>null</c> otherwise.</returns>
+    /// <returns>A <see cref="Type"/> instance if the base type was found, <see langword="null"/> otherwise.</returns>
     public static IEnumerable<Type> FindGenericBaseTypes(Type type!!, Type definition!!)
     {
         if (!definition.IsGenericTypeDefinition)

src/OpenIddict.Abstractions/Managers/IOpenIddictApplicationManager.cs

@@ -310,7 +310,7 @@ public interface IOpenIddictApplicationManager
     /// <param name="application">The application.</param>
     /// <param name="type">The expected client type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the application has the specified client type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the application has the specified client type, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasClientTypeAsync(object application, string type, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -319,7 +319,7 @@ public interface IOpenIddictApplicationManager
     /// <param name="application">The application.</param>
     /// <param name="type">The expected consent type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the application has the specified consent type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the application has the specified consent type, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasConsentTypeAsync(object application, string type, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -328,7 +328,7 @@ public interface IOpenIddictApplicationManager
     /// <param name="application">The application.</param>
     /// <param name="permission">The permission.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the application has been granted the specified permission, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the application has been granted the specified permission, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasPermissionAsync(object application, string permission, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -337,7 +337,7 @@ public interface IOpenIddictApplicationManager
     /// <param name="application">The application.</param>
     /// <param name="requirement">The requirement.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the requirement has been enforced for the specified application, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the requirement has been enforced for the specified application, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasRequirementAsync(object application, string requirement, CancellationToken cancellationToken = default);
 
     /// <summary>

src/OpenIddict.Abstractions/Managers/IOpenIddictAuthorizationManager.cs

@@ -289,7 +289,7 @@ public interface IOpenIddictAuthorizationManager
     /// <param name="authorization">The authorization.</param>
     /// <param name="scopes">The scopes.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the scopes are included in the authorization, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the scopes are included in the authorization, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasScopesAsync(object authorization, ImmutableArray<string> scopes, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -298,7 +298,7 @@ public interface IOpenIddictAuthorizationManager
     /// <param name="authorization">The authorization.</param>
     /// <param name="status">The expected status.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the authorization has the specified status, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the authorization has the specified status, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasStatusAsync(object authorization, string status, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -307,7 +307,7 @@ public interface IOpenIddictAuthorizationManager
     /// <param name="authorization">The authorization.</param>
     /// <param name="type">The expected type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the authorization has the specified type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the authorization has the specified type, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasTypeAsync(object authorization, string type, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -385,7 +385,7 @@ public interface IOpenIddictAuthorizationManager
     /// </summary>
     /// <param name="authorization">The authorization to revoke.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the authorization was successfully revoked, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the authorization was successfully revoked, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> TryRevokeAsync(object authorization, CancellationToken cancellationToken = default);
 
     /// <summary>

src/OpenIddict.Abstractions/Managers/IOpenIddictTokenManager.cs

@@ -324,7 +324,7 @@ public interface IOpenIddictTokenManager
     /// <param name="token">The token.</param>
     /// <param name="status">The expected status.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token has the specified status, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token has the specified status, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasStatusAsync(object token, string status, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -333,7 +333,7 @@ public interface IOpenIddictTokenManager
     /// <param name="token">The token.</param>
     /// <param name="type">The expected type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token has the specified type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token has the specified type, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasTypeAsync(object token, string type, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -342,7 +342,7 @@ public interface IOpenIddictTokenManager
     /// <param name="token">The token.</param>
     /// <param name="types">The expected types.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token has any of the specified types, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token has any of the specified types, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> HasTypeAsync(object token, ImmutableArray<string> types, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -416,7 +416,7 @@ public interface IOpenIddictTokenManager
     /// </summary>
     /// <param name="token">The token to redeem.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token was successfully redemeed, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token was successfully redemeed, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> TryRedeemAsync(object token, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -424,7 +424,7 @@ public interface IOpenIddictTokenManager
     /// </summary>
     /// <param name="token">The token to reject.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token was successfully redemeed, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token was successfully redemeed, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> TryRejectAsync(object token, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -432,7 +432,7 @@ public interface IOpenIddictTokenManager
     /// </summary>
     /// <param name="token">The token to revoke.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token was successfully revoked, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token was successfully revoked, <see langword="false"/> otherwise.</returns>
     ValueTask<bool> TryRevokeAsync(object token, CancellationToken cancellationToken = default);
 
     /// <summary>

src/OpenIddict.Abstractions/Primitives/OpenIddictConverter.cs

@@ -18,7 +18,7 @@ public class OpenIddictConverter : JsonConverter<OpenIddictMessage>
     /// Determines whether the specified type is supported by this converter.
     /// </summary>
     /// <param name="typeToConvert">The type to convert.</param>
-    /// <returns><c>true</c> if the type is supported, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the type is supported, <see langword="false"/> otherwise.</returns>
     public override bool CanConvert(Type typeToConvert!!)
     {
         return typeToConvert == typeof(OpenIddictMessage) ||

src/OpenIddict.Abstractions/Primitives/OpenIddictExtensions.cs

@@ -114,7 +114,7 @@ public static class OpenIddictExtensions
     /// See http://openid.net/specs/oauth-v2-multiple-response-types-1_0.html#none for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a response_type=none request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a response_type=none request, <see langword="false"/> otherwise.</returns>
     public static bool IsNoneFlow(this OpenIddictRequest request!!)
     {
         if (string.IsNullOrEmpty(request.ResponseType))
@@ -136,7 +136,7 @@ public static class OpenIddictExtensions
     /// See http://tools.ietf.org/html/rfc6749#section-4.1.1 for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a code flow request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a code flow request, <see langword="false"/> otherwise.</returns>
     public static bool IsAuthorizationCodeFlow(this OpenIddictRequest request!!)
     {
         if (string.IsNullOrEmpty(request.ResponseType))
@@ -159,7 +159,7 @@ public static class OpenIddictExtensions
     /// http://openid.net/specs/openid-connect-core-1_0.html for more information
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is an implicit flow request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is an implicit flow request, <see langword="false"/> otherwise.</returns>
     public static bool IsImplicitFlow(this OpenIddictRequest request!!)
     {
         if (string.IsNullOrEmpty(request.ResponseType))
@@ -208,7 +208,7 @@ public static class OpenIddictExtensions
     /// http://openid.net/specs/openid-connect-core-1_0.html for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is an hybrid flow request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is an hybrid flow request, <see langword="false"/> otherwise.</returns>
     public static bool IsHybridFlow(this OpenIddictRequest request!!)
     {
         if (string.IsNullOrEmpty(request.ResponseType))
@@ -268,8 +268,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns>
-    /// <c>true</c> if the request specified the fragment response mode or if
-    /// it's the default value for the requested flow, <c>false</c> otherwise.
+    /// <see langword="true"/> if the request specified the fragment response mode or if
+    /// it's the default value for the requested flow, <see langword="false"/> otherwise.
     /// </returns>
     public static bool IsFragmentResponseMode(this OpenIddictRequest request!!)
     {
@@ -296,8 +296,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns>
-    /// <c>true</c> if the request specified the query response mode or if
-    /// it's the default value for the requested flow, <c>false</c> otherwise.
+    /// <see langword="true"/> if the request specified the query response mode or if
+    /// it's the default value for the requested flow, <see langword="false"/> otherwise.
     /// </returns>
     public static bool IsQueryResponseMode(this OpenIddictRequest request!!)
     {
@@ -323,8 +323,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
     /// <returns>
-    /// <c>true</c> if the request specified the form post response mode or if
-    /// it's the default value for the requested flow, <c>false</c> otherwise.
+    /// <see langword="true"/> if the request specified the form post response mode or if
+    /// it's the default value for the requested flow, <see langword="false"/> otherwise.
     /// </returns>
     public static bool IsFormPostResponseMode(this OpenIddictRequest request!!)
         => string.Equals(request.ResponseMode, ResponseModes.FormPost, StringComparison.Ordinal);
@@ -334,7 +334,7 @@ public static class OpenIddictExtensions
     /// See http://tools.ietf.org/html/rfc6749#section-4.1.3 for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a code grant request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a code grant request, <see langword="false"/> otherwise.</returns>
     public static bool IsAuthorizationCodeGrantType(this OpenIddictRequest request!!)
         => string.Equals(request.GrantType, GrantTypes.AuthorizationCode, StringComparison.Ordinal);
 
@@ -343,7 +343,7 @@ public static class OpenIddictExtensions
     /// See http://tools.ietf.org/html/rfc6749#section-4.4.2 for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a client credentials grant request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a client credentials grant request, <see langword="false"/> otherwise.</returns>
     public static bool IsClientCredentialsGrantType(this OpenIddictRequest request!!)
         => string.Equals(request.GrantType, GrantTypes.ClientCredentials, StringComparison.Ordinal);
 
@@ -352,7 +352,7 @@ public static class OpenIddictExtensions
     /// See https://tools.ietf.org/html/rfc8628 for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a device code grant request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a device code grant request, <see langword="false"/> otherwise.</returns>
     public static bool IsDeviceCodeGrantType(this OpenIddictRequest request!!)
         => string.Equals(request.GrantType, GrantTypes.DeviceCode, StringComparison.Ordinal);
 
@@ -361,7 +361,7 @@ public static class OpenIddictExtensions
     /// See http://tools.ietf.org/html/rfc6749#section-4.3.2 for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a password grant request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a password grant request, <see langword="false"/> otherwise.</returns>
     public static bool IsPasswordGrantType(this OpenIddictRequest request!!)
         => string.Equals(request.GrantType, GrantTypes.Password, StringComparison.Ordinal);
 
@@ -370,7 +370,7 @@ public static class OpenIddictExtensions
     /// See http://tools.ietf.org/html/rfc6749#section-6 for more information.
     /// </summary>
     /// <param name="request">The <see cref="OpenIddictRequest"/> instance.</param>
-    /// <returns><c>true</c> if the request is a refresh token grant request, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the request is a refresh token grant request, <see langword="false"/> otherwise.</returns>
     public static bool IsRefreshTokenGrantType(this OpenIddictRequest request!!)
         => string.Equals(request.GrantType, GrantTypes.RefreshToken, StringComparison.Ordinal);
 
@@ -551,8 +551,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="identity">The <see cref="ClaimsIdentity"/> instance to filter.</param>
     /// <param name="filter">
-    /// The delegate filtering the claims: return <c>true</c>
-    /// to accept the claim, <c>false</c> to remove it.
+    /// The delegate filtering the claims: return <see langword="true"/>
+    /// to accept the claim, <see langword="false"/> to remove it.
     /// </param>
     public static ClaimsIdentity Clone(this ClaimsIdentity identity!!, Func<Claim, bool> filter!!)
     {
@@ -581,8 +581,8 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The <see cref="ClaimsPrincipal"/> instance to filter.</param>
     /// <param name="filter">
-    /// The delegate filtering the claims: return <c>true</c>
-    /// to accept the claim, <c>false</c> to remove it.
+    /// The delegate filtering the claims: return <see langword="true"/>
+    /// to accept the claim, <see langword="false"/> to remove it.
     /// </param>
     public static ClaimsPrincipal Clone(this ClaimsPrincipal principal!!, Func<Claim, bool> filter!!)
     {
@@ -704,7 +704,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="identity">The claims identity.</param>
     /// <param name="type">The claim type.</param>
-    /// <returns><c>true</c> if the identity contains at least one claim of the specified type.</returns>
+    /// <returns><see langword="true"/> if the identity contains at least one claim of the specified type.</returns>
     public static bool HasClaim(this ClaimsIdentity identity!!, string type)
     {
         if (string.IsNullOrEmpty(type))
@@ -736,7 +736,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <param name="type">The claim type.</param>
-    /// <returns><c>true</c> if the principal contains at least one claim of the specified type.</returns>
+    /// <returns><see langword="true"/> if the principal contains at least one claim of the specified type.</returns>
     public static bool HasClaim(this ClaimsPrincipal principal!!, string type)
     {
         if (string.IsNullOrEmpty(type))
@@ -902,7 +902,7 @@ public static class OpenIddictExtensions
     /// Gets the creation date stored in the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The creation date or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The creation date or <see langword="null"/> if the claim cannot be found.</returns>
     public static DateTimeOffset? GetCreationDate(this ClaimsPrincipal principal!!)
     {
         var claim = principal.FindFirst(Claims.Private.CreationDate);
@@ -923,7 +923,7 @@ public static class OpenIddictExtensions
     /// Gets the expiration date stored in the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The expiration date or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The expiration date or <see langword="null"/> if the claim cannot be found.</returns>
     public static DateTimeOffset? GetExpirationDate(this ClaimsPrincipal principal!!)
     {
         var claim = principal.FindFirst(Claims.Private.ExpirationDate);
@@ -976,7 +976,7 @@ public static class OpenIddictExtensions
     /// Gets the access token lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The access token lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The access token lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetAccessTokenLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.AccessTokenLifetime);
 
@@ -984,7 +984,7 @@ public static class OpenIddictExtensions
     /// Gets the authorization code lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The authorization code lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The authorization code lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetAuthorizationCodeLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.AuthorizationCodeLifetime);
 
@@ -992,7 +992,7 @@ public static class OpenIddictExtensions
     /// Gets the device code lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The device code lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The device code lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetDeviceCodeLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.DeviceCodeLifetime);
 
@@ -1000,7 +1000,7 @@ public static class OpenIddictExtensions
     /// Gets the identity token lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The identity token lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The identity token lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetIdentityTokenLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.IdentityTokenLifetime);
 
@@ -1008,7 +1008,7 @@ public static class OpenIddictExtensions
     /// Gets the refresh token lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The refresh token lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The refresh token lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetRefreshTokenLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.RefreshTokenLifetime);
 
@@ -1016,7 +1016,7 @@ public static class OpenIddictExtensions
     /// Gets the state token lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The state token lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The state token lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetStateTokenLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.StateTokenLifetime);
 
@@ -1024,7 +1024,7 @@ public static class OpenIddictExtensions
     /// Gets the user code lifetime associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The user code lifetime or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The user code lifetime or <see langword="null"/> if the claim cannot be found.</returns>
     public static TimeSpan? GetUserCodeLifetime(this ClaimsPrincipal principal)
         => GetLifetime(principal, Claims.Private.UserCodeLifetime);
 
@@ -1032,7 +1032,7 @@ public static class OpenIddictExtensions
     /// Gets the internal authorization identifier associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The unique identifier or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The unique identifier or <see langword="null"/> if the claim cannot be found.</returns>
     public static string? GetAuthorizationId(this ClaimsPrincipal principal)
         => principal.GetClaim(Claims.Private.AuthorizationId);
 
@@ -1040,7 +1040,7 @@ public static class OpenIddictExtensions
     /// Gets the internal token identifier associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The unique identifier or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The unique identifier or <see langword="null"/> if the claim cannot be found.</returns>
     public static string? GetTokenId(this ClaimsPrincipal principal)
         => principal.GetClaim(Claims.Private.TokenId);
 
@@ -1048,7 +1048,7 @@ public static class OpenIddictExtensions
     /// Gets the token type associated with the claims principal.
     /// </summary>
     /// <param name="principal">The claims principal.</param>
-    /// <returns>The token type or <c>null</c> if the claim cannot be found.</returns>
+    /// <returns>The token type or <see langword="null"/> if the claim cannot be found.</returns>
     public static string? GetTokenType(this ClaimsPrincipal principal)
         => principal.GetClaim(Claims.Private.TokenType);
 
@@ -1057,7 +1057,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <param name="audience">The audience.</param>
-    /// <returns><c>true</c> if the principal contains the given audience.</returns>
+    /// <returns><see langword="true"/> if the principal contains the given audience.</returns>
     public static bool HasAudience(this ClaimsPrincipal principal!!, string audience)
     {
         if (string.IsNullOrEmpty(audience))
@@ -1073,7 +1073,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <param name="presenter">The presenter.</param>
-    /// <returns><c>true</c> if the principal contains the given presenter.</returns>
+    /// <returns><see langword="true"/> if the principal contains the given presenter.</returns>
     public static bool HasPresenter(this ClaimsPrincipal principal!!, string presenter)
     {
         if (string.IsNullOrEmpty(presenter))
@@ -1089,7 +1089,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <param name="resource">The resource.</param>
-    /// <returns><c>true</c> if the principal contains the given resource.</returns>
+    /// <returns><see langword="true"/> if the principal contains the given resource.</returns>
     public static bool HasResource(this ClaimsPrincipal principal!!, string resource)
     {
         if (string.IsNullOrEmpty(resource))
@@ -1105,7 +1105,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <param name="scope">The scope.</param>
-    /// <returns><c>true</c> if the principal contains the given scope.</returns>
+    /// <returns><see langword="true"/> if the principal contains the given scope.</returns>
     public static bool HasScope(this ClaimsPrincipal principal!!, string scope)
     {
         if (string.IsNullOrEmpty(scope))
@@ -1121,7 +1121,7 @@ public static class OpenIddictExtensions
     /// </summary>
     /// <param name="principal">The claims principal.</param>
     /// <param name="type">The token type.</param>
-    /// <returns><c>true</c> if the token type matches the specified type.</returns>
+    /// <returns><see langword="true"/> if the token type matches the specified type.</returns>
     public static bool HasTokenType(this ClaimsPrincipal principal!!, string type)
     {
         if (string.IsNullOrEmpty(type))

src/OpenIddict.Abstractions/Primitives/OpenIddictMessage.cs

@@ -218,7 +218,7 @@ public class OpenIddictMessage
     /// Gets the value corresponding to a given parameter.
     /// </summary>
     /// <param name="name">The parameter name.</param>
-    /// <returns>The parameter value, or <c>null</c> if it cannot be found.</returns>
+    /// <returns>The parameter value, or <see langword="null"/> if it cannot be found.</returns>
     public OpenIddictParameter? GetParameter(string name)
     {
         if (string.IsNullOrEmpty(name))
@@ -245,7 +245,7 @@ public class OpenIddictMessage
     /// Determines whether the current message contains the specified parameter.
     /// </summary>
     /// <param name="name">The parameter name.</param>
-    /// <returns><c>true</c> if the parameter is present, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the parameter is present, <see langword="false"/> otherwise.</returns>
     public bool HasParameter(string name)
     {
         if (string.IsNullOrEmpty(name))
@@ -306,7 +306,7 @@ public class OpenIddictMessage
     /// </summary>
     /// <param name="name">The parameter name.</param>
     /// <param name="value">The parameter value.</param>
-    /// <returns><c>true</c> if the parameter could be found, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the parameter could be found, <see langword="false"/> otherwise.</returns>
     public bool TryGetParameter(string name, out OpenIddictParameter value)
     {
         if (string.IsNullOrEmpty(name))

src/OpenIddict.Abstractions/Primitives/OpenIddictParameter.cs

@@ -76,8 +76,8 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     public OpenIddictParameter? this[string name] => GetNamedParameter(name);
 
     /// <summary>
-    /// Gets the number of unnamed child items contained in the current parameter or
-    /// <c>0</c> if the parameter doesn't represent an array of strings or a JSON array.
+    /// Gets the number of unnamed child items contained in the current parameter
+    /// or 0 if the parameter doesn't represent an array of strings or a JSON array.
     /// </summary>
     public int Count => Value switch
     {
@@ -103,7 +103,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// instance is equal to the specified <see cref="OpenIddictParameter"/>.
     /// </summary>
     /// <param name="other">The other object to which to compare this instance.</param>
-    /// <returns><c>true</c> if the two instances are equal, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the two instances are equal, <see langword="false"/> otherwise.</returns>
     public bool Equals(OpenIddictParameter other)
     {
         return (left: Value, right: other.Value) switch
@@ -214,7 +214,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// instance is equal to the specified <see cref="object"/>.
     /// </summary>
     /// <param name="obj">The other object to which to compare this instance.</param>
-    /// <returns><c>true</c> if the two instances are equal, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the two instances are equal, <see langword="false"/> otherwise.</returns>
     public override bool Equals(object? obj) => obj is OpenIddictParameter parameter && Equals(parameter);
 
     /// <summary>
@@ -431,7 +431,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// </summary>
     /// <param name="name">The name of the child item.</param>
     /// <param name="value">An <see cref="OpenIddictParameter"/> instance containing the item value.</param>
-    /// <returns><c>true</c> if the parameter could be found, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the parameter could be found, <see langword="false"/> otherwise.</returns>
     public bool TryGetNamedParameter(string name, out OpenIddictParameter value)
     {
         if (string.IsNullOrEmpty(name))
@@ -457,7 +457,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// </summary>
     /// <param name="index">The index of the child item.</param>
     /// <param name="value">An <see cref="OpenIddictParameter"/> instance containing the item value.</param>
-    /// <returns><c>true</c> if the parameter could be found, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the parameter could be found, <see langword="false"/> otherwise.</returns>
     public bool TryGetUnnamedParameter(int index, out OpenIddictParameter value)
     {
         if (index < 0)
@@ -548,7 +548,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// </summary>
     /// <param name="left">The first instance.</param>
     /// <param name="right">The second instance.</param>
-    /// <returns><c>true</c> if the two instances are equal, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the two instances are equal, <see langword="false"/> otherwise.</returns>
     public static bool operator ==(OpenIddictParameter left, OpenIddictParameter right) => left.Equals(right);
 
     /// <summary>
@@ -556,7 +556,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// </summary>
     /// <param name="left">The first instance.</param>
     /// <param name="right">The second instance.</param>
-    /// <returns><c>true</c> if the two instances are not equal, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the two instances are not equal, <see langword="false"/> otherwise.</returns>
     public static bool operator !=(OpenIddictParameter left, OpenIddictParameter right) => !left.Equals(right);
 
     /// <summary>
@@ -863,7 +863,7 @@ public readonly struct OpenIddictParameter : IEquatable<OpenIddictParameter>
     /// Determines whether a parameter is null or empty.
     /// </summary>
     /// <param name="parameter">The parameter.</param>
-    /// <returns><c>true</c> if the parameter is null or empty, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the parameter is null or empty, <see langword="false"/> otherwise.</returns>
     public static bool IsNullOrEmpty(OpenIddictParameter parameter)
     {
         return parameter.Value switch

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreBuilder.cs

@@ -78,7 +78,7 @@ public class OpenIddictClientAspNetCoreBuilder
     /// Determines whether the specified object is equal to the current object.
     /// </summary>
     /// <param name="obj">The object to compare with the current object.</param>
-    /// <returns><c>true</c> if the specified object is equal to the current object; otherwise, false.</returns>
+    /// <returns><see langword="true"/> if the specified object is equal to the current object; otherwise, false.</returns>
     [EditorBrowsable(EditorBrowsableState.Never)]
     public override bool Equals(object? obj) => base.Equals(obj);
 

src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHelpers.cs

@@ -18,7 +18,7 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// Retrieves the <see cref="HttpRequest"/> instance stored in the <see cref="OpenIddictClientTransaction"/> properties.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpRequest? GetHttpRequest(this OpenIddictClientTransaction transaction!!)
     {
         if (!transaction.Properties.TryGetValue(typeof(HttpRequest).FullName!, out object? property))
@@ -48,7 +48,7 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// Retrieves the <see cref="OpenIddictRequest"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictRequest? GetOpenIddictClientRequest(this HttpContext context!!)
     {
         return context.Features.Get<OpenIddictClientAspNetCoreFeature>()?.Transaction?.Request;
@@ -58,7 +58,7 @@ public static class OpenIddictClientAspNetCoreHelpers
     /// Retrieves the <see cref="OpenIddictResponse"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictResponse"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictResponse"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictResponse? GetOpenIddictClientResponse(this HttpContext context!!)
     {
         return context.Features.Get<OpenIddictClientAspNetCoreFeature>()?.Transaction?.Response;

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpBuilder.cs

@@ -53,7 +53,7 @@ public class OpenIddictClientSystemNetHttpBuilder
     /// Determines whether the specified object is equal to the current object.
     /// </summary>
     /// <param name="obj">The object to compare with the current object.</param>
-    /// <returns><c>true</c> if the specified object is equal to the current object; otherwise, false.</returns>
+    /// <returns><see langword="true"/> if the specified object is equal to the current object; otherwise, false.</returns>
     [EditorBrowsable(EditorBrowsableState.Never)]
     public override bool Equals(object? obj) => base.Equals(obj);
 

src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpHelpers.cs

@@ -17,7 +17,7 @@ public static class OpenIddictClientSystemNetHttpHelpers
     /// Gets the <see cref="HttpRequestMessage"/> associated with the current context.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpRequestMessage"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpRequestMessage"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpRequestMessage? GetHttpRequestMessage(this OpenIddictClientTransaction transaction)
         => transaction.GetProperty<HttpRequestMessage>(typeof(HttpRequestMessage).FullName!);
 
@@ -25,7 +25,7 @@ public static class OpenIddictClientSystemNetHttpHelpers
     /// Gets the <see cref="HttpResponseMessage"/> associated with the current context.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpResponseMessage"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpResponseMessage"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpResponseMessage? GetHttpResponseMessage(this OpenIddictClientTransaction transaction)
         => transaction.GetProperty<HttpResponseMessage>(typeof(HttpResponseMessage).FullName!);
 }

src/OpenIddict.Client/OpenIddictClientBuilder.cs

@@ -122,7 +122,7 @@ public class OpenIddictClientBuilder
     {
         // If the encryption key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
-            asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
+            asymmetricSecurityKey.PrivateKeyStatus is PrivateKeyStatus.DoesNotExist)
         {
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0055));
         }
@@ -482,7 +482,7 @@ public class OpenIddictClientBuilder
     {
         // If the signing key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
-            asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
+            asymmetricSecurityKey.PrivateKeyStatus is PrivateKeyStatus.DoesNotExist)
         {
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0067));
         }
@@ -909,7 +909,7 @@ public class OpenIddictClientBuilder
     /// Sets the state token lifetime, after which authorization callbacks
     /// using an expired state token will be automatically rejected by OpenIddict.
     /// Using long-lived state tokens or tokens that never expire is not recommended.
-    /// While discouraged, <c>null</c> can be specified to issue tokens that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue tokens that never expire.
     /// </summary>
     /// <param name="lifetime">The access token lifetime.</param>
     /// <returns>The <see cref="OpenIddictClientBuilder"/>.</returns>
@@ -920,7 +920,7 @@ public class OpenIddictClientBuilder
     /// Determines whether the specified object is equal to the current object.
     /// </summary>
     /// <param name="obj">The object to compare with the current object.</param>
-    /// <returns><c>true</c> if the specified object is equal to the current object; otherwise, false.</returns>
+    /// <returns><see langword="true"/> if the specified object is equal to the current object; otherwise, false.</returns>
     [EditorBrowsable(EditorBrowsableState.Never)]
     public override bool Equals(object? obj) => base.Equals(obj);
 

src/OpenIddict.Client/OpenIddictClientEvents.Authentication.cs

@@ -80,7 +80,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the request or <c>null</c> if it was extracted yet.
+        /// Gets or sets the request or <see langword="null"/> if it was extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -170,7 +170,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {

src/OpenIddict.Client/OpenIddictClientEvents.Discovery.cs

@@ -82,7 +82,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {
@@ -200,7 +200,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {

src/OpenIddict.Client/OpenIddictClientEvents.Exchange.cs

@@ -92,7 +92,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {

src/OpenIddict.Client/OpenIddictClientEvents.Protection.cs

@@ -26,7 +26,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it is not available.
+        /// Gets or sets the request, or <see langword="null"/> if it is not available.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -79,7 +79,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it is not available.
+        /// Gets or sets the request, or <see langword="null"/> if it is not available.
         /// </summary>
         public OpenIddictRequest? Request
         {

src/OpenIddict.Client/OpenIddictClientEvents.Userinfo.cs

@@ -82,7 +82,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {

src/OpenIddict.Client/OpenIddictClientEvents.cs

@@ -224,7 +224,7 @@ public static partial class OpenIddictClientEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -709,7 +709,7 @@ public static partial class OpenIddictClientEvents
         /// <summary>
         /// Gets or sets the generated state token, if applicable.
         /// The access token will only be returned if
-        /// <see cref="IncludeStateToken"/> is set to <c>true</c>.
+        /// <see cref="IncludeStateToken"/> is set to <see langword="true"/>.
         /// </summary>
         public string? StateToken { get; set; }
 

src/OpenIddict.Client/OpenIddictClientHelpers.cs

@@ -17,7 +17,7 @@ public static class OpenIddictClientHelpers
     /// <typeparam name="TProperty">The type of the property.</typeparam>
     /// <param name="transaction">The client transaction.</param>
     /// <param name="name">The property name.</param>
-    /// <returns>The property value or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The property value or <see langword="null"/> if it couldn't be found.</returns>
     public static TProperty? GetProperty<TProperty>(
         this OpenIddictClientTransaction transaction!!, string name) where TProperty : class
     {

src/OpenIddict.Core/Managers/OpenIddictApplicationManager.cs

@@ -535,7 +535,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
         TApplication application!!, CultureInfo culture!!, CancellationToken cancellationToken = default)
     {
         var names = await Store.GetDisplayNamesAsync(application, cancellationToken);
-        if (names is not { IsEmpty: false })
+        if (names is not { Count: > 0 })
         {
             return await Store.GetDisplayNameAsync(application, cancellationToken);
         }
@@ -626,7 +626,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="application">The application.</param>
     /// <param name="type">The expected client type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the application has the specified client type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the application has the specified client type, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasClientTypeAsync(
         TApplication application!!, string type, CancellationToken cancellationToken = default)
     {
@@ -644,7 +644,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="application">The application.</param>
     /// <param name="type">The expected consent type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the application has the specified consent type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the application has the specified consent type, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasConsentTypeAsync(
         TApplication application!!, string type, CancellationToken cancellationToken = default)
     {
@@ -662,7 +662,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="application">The application.</param>
     /// <param name="permission">The permission.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the application has been granted the specified permission, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the application has been granted the specified permission, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasPermissionAsync(
         TApplication application!!, string permission, CancellationToken cancellationToken = default)
     {
@@ -680,7 +680,7 @@ public class OpenIddictApplicationManager<TApplication> : IOpenIddictApplication
     /// <param name="application">The application.</param>
     /// <param name="requirement">The requirement.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the requirement has been enforced for the specified application, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the requirement has been enforced for the specified application, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasRequirementAsync(
         TApplication application!!, string requirement, CancellationToken cancellationToken = default)
     {

src/OpenIddict.Core/Managers/OpenIddictAuthorizationManager.cs

@@ -714,7 +714,7 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="authorization">The authorization.</param>
     /// <param name="scopes">The scopes.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the scopes are included in the authorization, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the scopes are included in the authorization, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasScopesAsync(TAuthorization authorization!!,
         ImmutableArray<string> scopes, CancellationToken cancellationToken = default)
         => new HashSet<string>(await Store.GetScopesAsync(
@@ -726,7 +726,7 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="authorization">The authorization.</param>
     /// <param name="status">The expected status.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the authorization has the specified status, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the authorization has the specified status, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasStatusAsync(TAuthorization authorization!!,
         string status, CancellationToken cancellationToken = default)
     {
@@ -744,7 +744,7 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// <param name="authorization">The authorization.</param>
     /// <param name="type">The expected type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the authorization has the specified type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the authorization has the specified type, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasTypeAsync(
         TAuthorization authorization!!, string type, CancellationToken cancellationToken = default)
     {
@@ -862,7 +862,7 @@ public class OpenIddictAuthorizationManager<TAuthorization> : IOpenIddictAuthori
     /// </summary>
     /// <param name="authorization">The authorization to revoke.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the authorization was successfully revoked, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the authorization was successfully revoked, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> TryRevokeAsync(TAuthorization authorization!!, CancellationToken cancellationToken = default)
     {
         var status = await Store.GetStatusAsync(authorization, cancellationToken);

src/OpenIddict.Core/Managers/OpenIddictScopeManager.cs

@@ -450,7 +450,7 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
         TScope scope!!, CultureInfo culture!!, CancellationToken cancellationToken = default)
     {
         var names = await Store.GetDisplayNamesAsync(scope, cancellationToken);
-        if (names is not { IsEmpty: false })
+        if (names is not { Count: > 0 })
         {
             return await Store.GetDisplayNameAsync(scope, cancellationToken);
         }
@@ -500,7 +500,7 @@ public class OpenIddictScopeManager<TScope> : IOpenIddictScopeManager where TSco
         TScope scope!!, CultureInfo culture!!, CancellationToken cancellationToken = default)
     {
         var descriptions = await Store.GetDescriptionsAsync(scope, cancellationToken);
-        if (descriptions is not { IsEmpty: false })
+        if (descriptions is not { Count: > 0 })
         {
             return await Store.GetDescriptionAsync(scope, cancellationToken);
         }

src/OpenIddict.Core/Managers/OpenIddictTokenManager.cs

@@ -729,7 +729,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="token">The token.</param>
     /// <param name="status">The expected status.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token has the specified status, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token has the specified status, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasStatusAsync(TToken token!!, string status, CancellationToken cancellationToken = default)
     {
         if (string.IsNullOrEmpty(status))
@@ -746,7 +746,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="token">The token.</param>
     /// <param name="type">The expected type.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token has the specified type, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token has the specified type, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasTypeAsync(TToken token!!, string type, CancellationToken cancellationToken = default)
     {
         if (string.IsNullOrEmpty(type))
@@ -763,7 +763,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// <param name="token">The token.</param>
     /// <param name="types">The expected types.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token has any of the specified types, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token has any of the specified types, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> HasTypeAsync(TToken token!!, ImmutableArray<string> types, CancellationToken cancellationToken = default)
     {
         var type = await Store.GetTypeAsync(token, cancellationToken);
@@ -892,7 +892,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// </summary>
     /// <param name="token">The token to redeem.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token was successfully redemeed, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token was successfully redemeed, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> TryRedeemAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
         // If the token doesn't have a redemption date attached, this likely means it's
@@ -933,7 +933,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// </summary>
     /// <param name="token">The token to reject.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token was successfully redemeed, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token was successfully redemeed, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> TryRejectAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
         await Store.SetStatusAsync(token, Statuses.Rejected, cancellationToken);
@@ -967,7 +967,7 @@ public class OpenIddictTokenManager<TToken> : IOpenIddictTokenManager where TTok
     /// </summary>
     /// <param name="token">The token to revoke.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> that can be used to abort the operation.</param>
-    /// <returns><c>true</c> if the token was successfully revoked, <c>false</c> otherwise.</returns>
+    /// <returns><see langword="true"/> if the token was successfully revoked, <see langword="false"/> otherwise.</returns>
     public virtual async ValueTask<bool> TryRevokeAsync(TToken token!!, CancellationToken cancellationToken = default)
     {
         await Store.SetStatusAsync(token, Statuses.Revoked, cancellationToken);

src/OpenIddict.Core/OpenIddictCoreOptions.cs

@@ -39,7 +39,7 @@ public class OpenIddictCoreOptions
     /// Gets or sets a boolean indicating whether additional filtering should be disabled,
     /// so that the OpenIddict managers don't execute a second check to ensure the results
     /// returned by the stores exactly match the specified query filters, casing included.
-    /// This property SHOULD NOT be set to <c>true</c> except when the underlying stores
+    /// This property SHOULD NOT be set to <see langword="true"/> except when the underlying stores
     /// are guaranteed to execute case-sensitive filtering at the database level.
     /// Disabling this feature MAY result in security vulnerabilities in the other cases.
     /// </summary>
@@ -56,7 +56,7 @@ public class OpenIddictCoreOptions
     /// Gets or sets the maximum number of cached entries allowed. When the threshold
     /// is reached, the cache is automatically compacted to ensure it doesn't grow
     /// abnormally and doesn't cause a memory starvation or out-of-memory exceptions.
-    /// This property is not used when <see cref="DisableEntityCaching"/> is <c>true</c>.
+    /// This property is not used when <see cref="DisableEntityCaching"/> is <see langword="true"/>.
     /// </summary>
     public int EntityCacheLimit { get; set; } = 250;
 }

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkApplication.cs

@@ -87,7 +87,7 @@ public class OpenIddictEntityFrameworkApplication<TKey, TAuthorization, TToken>
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current application.
+    /// or <see langword="null"/> if no bag was associated with the current application.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkAuthorization.cs

@@ -51,7 +51,7 @@ public class OpenIddictEntityFrameworkAuthorization<TKey, TApplication, TToken>
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current authorization.
+    /// or <see langword="null"/> if no bag was associated with the current authorization.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkScope.cs

@@ -66,7 +66,7 @@ public class OpenIddictEntityFrameworkScope<TKey> where TKey : notnull, IEquatab
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current scope.
+    /// or <see langword="null"/> if no bag was associated with the current scope.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFramework.Models/OpenIddictEntityFrameworkToken.cs

@@ -68,7 +68,7 @@ public class OpenIddictEntityFrameworkToken<TKey, TApplication, TAuthorization>
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current token.
+    /// or <see langword="null"/> if no bag was associated with the current token.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkAuthorizationStore.cs

@@ -350,7 +350,7 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
         if (authorization.Application is null)
         {
             var reference = Context.Entry(authorization).Reference(entry => entry.Application);
-            if (reference.EntityEntry.State == EntityState.Detached)
+            if (reference.EntityEntry.State is EntityState.Detached)
             {
                 return null;
             }
@@ -598,7 +598,7 @@ public class OpenIddictEntityFrameworkAuthorizationStore<TAuthorization, TApplic
             if (authorization.Application is null)
             {
                 var reference = Context.Entry(authorization).Reference(entry => entry.Application);
-                if (reference.EntityEntry.State == EntityState.Detached)
+                if (reference.EntityEntry.State is EntityState.Detached)
                 {
                     return;
                 }

src/OpenIddict.EntityFramework/Stores/OpenIddictEntityFrameworkTokenStore.cs

@@ -290,7 +290,7 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
         if (token.Application is null)
         {
             var reference = Context.Entry(token).Reference(entry => entry.Application);
-            if (reference.EntityEntry.State == EntityState.Detached)
+            if (reference.EntityEntry.State is EntityState.Detached)
             {
                 return null;
             }
@@ -321,7 +321,7 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
         if (token.Authorization is null)
         {
             var reference = Context.Entry(token).Reference(entry => entry.Authorization);
-            if (reference.EntityEntry.State == EntityState.Detached)
+            if (reference.EntityEntry.State is EntityState.Detached)
             {
                 return null;
             }
@@ -541,7 +541,7 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
             if (token.Application is null)
             {
                 var reference = Context.Entry(token).Reference(entry => entry.Application);
-                if (reference.EntityEntry.State == EntityState.Detached)
+                if (reference.EntityEntry.State is EntityState.Detached)
                 {
                     return;
                 }
@@ -569,7 +569,7 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
             if (token.Authorization is null)
             {
                 var reference = Context.Entry(token).Reference(entry => entry.Authorization);
-                if (reference.EntityEntry.State == EntityState.Detached)
+                if (reference.EntityEntry.State is EntityState.Detached)
                 {
                     return;
                 }
@@ -609,7 +609,7 @@ public class OpenIddictEntityFrameworkTokenStore<TToken, TApplication, TAuthoriz
     public virtual ValueTask SetPropertiesAsync(TToken token!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (properties is not { IsEmpty: false })
+        if (properties is not { Count: > 0 })
         {
             token.Properties = null;
 

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreApplication.cs

@@ -95,7 +95,7 @@ public class OpenIddictEntityFrameworkCoreApplication<TKey, TAuthorization, TTok
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current application.
+    /// or <see langword="null"/> if no bag was associated with the current application.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreAuthorization.cs

@@ -59,7 +59,7 @@ public class OpenIddictEntityFrameworkCoreAuthorization<TKey, TApplication, TTok
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current authorization.
+    /// or <see langword="null"/> if no bag was associated with the current authorization.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreScope.cs

@@ -66,7 +66,7 @@ public class OpenIddictEntityFrameworkCoreScope<TKey> where TKey : notnull, IEqu
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current scope.
+    /// or <see langword="null"/> if no bag was associated with the current scope.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFrameworkCore.Models/OpenIddictEntityFrameworkCoreToken.cs

@@ -76,7 +76,7 @@ public class OpenIddictEntityFrameworkCoreToken<TKey, TApplication, TAuthorizati
 
     /// <summary>
     /// Gets or sets the additional properties serialized as a JSON object,
-    /// or <c>null</c> if no bag was associated with the current token.
+    /// or <see langword="null"/> if no bag was associated with the current token.
     /// </summary>
     public virtual string? Properties { get; set; }
 

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreAuthorizationStore.cs

@@ -415,7 +415,7 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
         if (authorization.Application is null)
         {
             var reference = Context.Entry(authorization).Reference(entry => entry.Application);
-            if (reference.EntityEntry.State == EntityState.Detached)
+            if (reference.EntityEntry.State is EntityState.Detached)
             {
                 return null;
             }
@@ -683,7 +683,7 @@ public class OpenIddictEntityFrameworkCoreAuthorizationStore<TAuthorization, TAp
             if (authorization.Application is null)
             {
                 var reference = Context.Entry(authorization).Reference(entry => entry.Application);
-                if (reference.EntityEntry.State == EntityState.Detached)
+                if (reference.EntityEntry.State is EntityState.Detached)
                 {
                     return;
                 }

src/OpenIddict.EntityFrameworkCore/Stores/OpenIddictEntityFrameworkCoreTokenStore.cs

@@ -339,7 +339,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
         if (token.Application is null)
         {
             var reference = Context.Entry(token).Reference(entry => entry.Application);
-            if (reference.EntityEntry.State == EntityState.Detached)
+            if (reference.EntityEntry.State is EntityState.Detached)
             {
                 return null;
             }
@@ -370,7 +370,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
         if (token.Authorization is null)
         {
             var reference = Context.Entry(token).Reference(entry => entry.Authorization);
-            if (reference.EntityEntry.State == EntityState.Detached)
+            if (reference.EntityEntry.State is EntityState.Detached)
             {
                 return null;
             }
@@ -606,7 +606,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
             if (token.Application is null)
             {
                 var reference = Context.Entry(token).Reference(entry => entry.Application);
-                if (reference.EntityEntry.State == EntityState.Detached)
+                if (reference.EntityEntry.State is EntityState.Detached)
                 {
                     return;
                 }
@@ -639,7 +639,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
             if (token.Authorization is null)
             {
                 var reference = Context.Entry(token).Reference(entry => entry.Authorization);
-                if (reference.EntityEntry.State == EntityState.Detached)
+                if (reference.EntityEntry.State is EntityState.Detached)
                 {
                     return;
                 }
@@ -679,7 +679,7 @@ public class OpenIddictEntityFrameworkCoreTokenStore<TToken, TApplication, TAuth
     public virtual ValueTask SetPropertiesAsync(TToken token!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (properties is not { IsEmpty: false })
+        if (properties is not { Count: > 0 })
         {
             token.Properties = null;
 

src/OpenIddict.MongoDb/Stores/OpenIddictMongoDbTokenStore.cs

@@ -545,7 +545,7 @@ public class OpenIddictMongoDbTokenStore<TToken> : IOpenIddictTokenStore<TToken>
     public virtual ValueTask SetPropertiesAsync(TToken token!!,
         ImmutableDictionary<string, JsonElement> properties, CancellationToken cancellationToken)
     {
-        if (properties is not { IsEmpty: false })
+        if (properties is not { Count: > 0 })
         {
             token.Properties = null;
 

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreHelpers.cs

@@ -18,7 +18,7 @@ public static class OpenIddictServerAspNetCoreHelpers
     /// Retrieves the <see cref="HttpRequest"/> instance stored in the <see cref="OpenIddictServerTransaction"/> properties.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpRequest? GetHttpRequest(this OpenIddictServerTransaction transaction!!)
     {
         if (!transaction.Properties.TryGetValue(typeof(HttpRequest).FullName!, out object? property))
@@ -48,7 +48,7 @@ public static class OpenIddictServerAspNetCoreHelpers
     /// Retrieves the <see cref="OpenIddictRequest"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictRequest? GetOpenIddictServerRequest(this HttpContext context!!)
     {
         return context.Features.Get<OpenIddictServerAspNetCoreFeature>()?.Transaction?.Request;
@@ -58,7 +58,7 @@ public static class OpenIddictServerAspNetCoreHelpers
     /// Retrieves the <see cref="OpenIddictResponse"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictResponse"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictResponse"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictResponse? GetOpenIddictServerResponse(this HttpContext context!!)
     {
         return context.Features.Get<OpenIddictServerAspNetCoreFeature>()?.Transaction?.Response;

src/OpenIddict.Server.AspNetCore/OpenIddictServerAspNetCoreOptions.cs

@@ -16,7 +16,7 @@ public class OpenIddictServerAspNetCoreOptions : AuthenticationSchemeOptions
 {
     /// <summary>
     /// Gets or sets a boolean indicating whether incoming requests arriving on insecure endpoints should be rejected.
-    /// By default, this property is set to <c>false</c> to help mitigate man-in-the-middle attacks.
+    /// By default, this property is set to <see langword="false"/> to help mitigate man-in-the-middle attacks.
     /// </summary>
     public bool DisableTransportSecurityRequirement { get; set; }
 

src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionOptions.cs

@@ -17,7 +17,7 @@ public class OpenIddictServerDataProtectionOptions
     /// <summary>
     /// Gets or sets the data protection provider used to create the default
     /// data protectors used by the OpenIddict Data Protection server services.
-    /// When this property is set to <c>null</c>, the data protection provider
+    /// When this property is set to <see langword="null"/>, the data protection provider
     /// is directly retrieved from the dependency injection container.
     /// </summary>
     public IDataProtectionProvider DataProtectionProvider { get; set; } = default!;
@@ -30,31 +30,31 @@ public class OpenIddictServerDataProtectionOptions
 
     /// <summary>
     /// Gets or sets a boolean indicating whether the default access token format should be
-    /// used when issuing new access tokens. This property is set to <c>false</c> by default.
+    /// used when issuing new access tokens. This property is set to <see langword="false"/> by default.
     /// </summary>
     public bool PreferDefaultAccessTokenFormat { get; set; }
 
     /// <summary>
     /// Gets or sets a boolean indicating whether the default authorization code format should be
-    /// used when issuing new authorization codes. This property is set to <c>false</c> by default.
+    /// used when issuing new authorization codes. This property is set to <see langword="false"/> by default.
     /// </summary>
     public bool PreferDefaultAuthorizationCodeFormat { get; set; }
 
     /// <summary>
     /// Gets or sets a boolean indicating whether the default device code format should be
-    /// used when issuing new device codes. This property is set to <c>false</c> by default.
+    /// used when issuing new device codes. This property is set to <see langword="false"/> by default.
     /// </summary>
     public bool PreferDefaultDeviceCodeFormat { get; set; }
 
     /// <summary>
     /// Gets or sets a boolean indicating whether the default refresh token format should be
-    /// used when issuing new refresh tokens. This property is set to <c>false</c> by default.
+    /// used when issuing new refresh tokens. This property is set to <see langword="false"/> by default.
     /// </summary>
     public bool PreferDefaultRefreshTokenFormat { get; set; }
 
     /// <summary>
     /// Gets or sets a boolean indicating whether the default user code format should be
-    /// used when issuing new user codes. This property is set to <c>false</c> by default.
+    /// used when issuing new user codes. This property is set to <see langword="false"/> by default.
     /// </summary>
     public bool PreferDefaultUserCodeFormat { get; set; }
 }

src/OpenIddict.Server.Owin/OpenIddictServerOwinHelpers.cs

@@ -28,7 +28,7 @@ public static class OpenIddictServerOwinHelpers
     /// Retrieves the <see cref="IOwinRequest"/> instance stored in the <see cref="OpenIddictServerTransaction"/> properties.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="IOwinRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="IOwinRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static IOwinRequest? GetOwinRequest(this OpenIddictServerTransaction transaction!!)
     {
         if (!transaction.Properties.TryGetValue(typeof(IOwinRequest).FullName!, out object? property))
@@ -56,7 +56,7 @@ public static class OpenIddictServerOwinHelpers
     /// Retrieves the <see cref="OpenIddictRequest"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictRequest? GetOpenIddictServerRequest(this IOwinContext context!!)
         => context.Get<OpenIddictServerTransaction>(typeof(OpenIddictServerTransaction).FullName)?.Request;
 
@@ -64,7 +64,7 @@ public static class OpenIddictServerOwinHelpers
     /// Retrieves the <see cref="OpenIddictResponse"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictResponse"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictResponse"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictResponse? GetOpenIddictServerResponse(this IOwinContext context!!)
         => context.Get<OpenIddictServerTransaction>(typeof(OpenIddictServerTransaction).FullName)?.Response;
 }

src/OpenIddict.Server.Owin/OpenIddictServerOwinOptions.cs

@@ -23,7 +23,7 @@ public class OpenIddictServerOwinOptions : AuthenticationOptions
 
     /// <summary>
     /// Gets or sets a boolean indicating whether incoming requests arriving on insecure endpoints should be rejected.
-    /// By default, this property is set to <c>false</c> to help mitigate man-in-the-middle attacks.
+    /// By default, this property is set to <see langword="false"/> to help mitigate man-in-the-middle attacks.
     /// </summary>
     public bool DisableTransportSecurityRequirement { get; set; }
 

src/OpenIddict.Server/OpenIddictServerBuilder.cs

@@ -131,7 +131,7 @@ public class OpenIddictServerBuilder
     {
         // If the encryption key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
-            asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
+            asymmetricSecurityKey.PrivateKeyStatus is PrivateKeyStatus.DoesNotExist)
         {
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0055));
         }
@@ -491,7 +491,7 @@ public class OpenIddictServerBuilder
     {
         // If the signing key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
-            asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
+            asymmetricSecurityKey.PrivateKeyStatus is PrivateKeyStatus.DoesNotExist)
         {
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0067));
         }
@@ -1505,7 +1505,7 @@ public class OpenIddictServerBuilder
     /// a new access token by making a grant_type=refresh_token token request
     /// or a prompt=none authorization request, depending on the selected flow.
     /// Using long-lived access tokens or tokens that never expire is not recommended.
-    /// While discouraged, <c>null</c> can be specified to issue tokens that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue tokens that never expire.
     /// </summary>
     /// <param name="lifetime">The access token lifetime.</param>
     /// <returns>The <see cref="OpenIddictServerBuilder"/>.</returns>
@@ -1516,7 +1516,7 @@ public class OpenIddictServerBuilder
     /// Sets the authorization code lifetime, after which client applications
     /// are unable to send a grant_type=authorization_code token request.
     /// Using short-lived authorization codes is strongly recommended.
-    /// While discouraged, <c>null</c> can be specified to issue codes that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue codes that never expire.
     /// </summary>
     /// <param name="lifetime">The authorization code lifetime.</param>
     /// <returns>The <see cref="OpenIddictServerBuilder"/>.</returns>
@@ -1527,7 +1527,7 @@ public class OpenIddictServerBuilder
     /// Sets the device code lifetime, after which client applications are unable to
     /// send a grant_type=urn:ietf:params:oauth:grant-type:device_code token request.
     /// Using short-lived device codes is strongly recommended.
-    /// While discouraged, <c>null</c> can be specified to issue codes that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue codes that never expire.
     /// </summary>
     /// <param name="lifetime">The authorization code lifetime.</param>
     /// <returns>The <see cref="OpenIddictServerBuilder"/>.</returns>
@@ -1537,7 +1537,7 @@ public class OpenIddictServerBuilder
     /// <summary>
     /// Sets the identity token lifetime, after which client
     /// applications should refuse processing identity tokens.
-    /// While discouraged, <c>null</c> can be specified to issue tokens that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue tokens that never expire.
     /// </summary>
     /// <param name="lifetime">The identity token lifetime.</param>
     /// <returns>The <see cref="OpenIddictServerBuilder"/>.</returns>
@@ -1549,7 +1549,7 @@ public class OpenIddictServerBuilder
     /// a new authorization from the user. When sliding expiration is enabled,
     /// a new refresh token is always issued to the client application,
     /// which prolongs the validity period of the refresh token.
-    /// While discouraged, <c>null</c> can be specified to issue tokens that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue tokens that never expire.
     /// </summary>
     /// <param name="lifetime">The refresh token lifetime.</param>
     /// <returns>The <see cref="OpenIddictServerBuilder"/>.</returns>
@@ -1568,7 +1568,7 @@ public class OpenIddictServerBuilder
     /// <summary>
     /// Sets the user code lifetime, after which they'll no longer be considered valid.
     /// Using short-lived device codes is strongly recommended.
-    /// While discouraged, <c>null</c> can be specified to issue codes that never expire.
+    /// While discouraged, <see langword="null"/> can be specified to issue codes that never expire.
     /// </summary>
     /// <param name="lifetime">The authorization code lifetime.</param>
     /// <returns>The <see cref="OpenIddictServerBuilder"/>.</returns>

src/OpenIddict.Server/OpenIddictServerEvents.Authentication.cs

@@ -25,7 +25,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request or <c>null</c> if it was extracted yet.
+        /// Gets or sets the request or <see langword="null"/> if it was extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -153,7 +153,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -187,7 +187,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response?.Error;
 

src/OpenIddict.Server/OpenIddictServerEvents.Device.cs

@@ -25,7 +25,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -119,7 +119,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -139,7 +139,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }
@@ -159,7 +159,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -263,7 +263,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -283,7 +283,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }

src/OpenIddict.Server/OpenIddictServerEvents.Discovery.cs

@@ -25,7 +25,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -206,7 +206,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -226,7 +226,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }
@@ -246,7 +246,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -331,7 +331,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -351,7 +351,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }

src/OpenIddict.Server/OpenIddictServerEvents.Exchange.cs

@@ -25,7 +25,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -125,7 +125,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -145,7 +145,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }

src/OpenIddict.Server/OpenIddictServerEvents.Introspection.cs

@@ -25,7 +25,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -59,7 +59,7 @@ public static partial class OpenIddictServerEvents
 
         /// <summary>
         /// Gets the optional token_type_hint parameter extracted from the
-        /// introspection request, or <c>null</c> if it cannot be found.
+        /// introspection request, or <see langword="null"/> if it cannot be found.
         /// </summary>
         public string? TokenTypeHint => Request?.TokenTypeHint;
 
@@ -182,7 +182,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -202,7 +202,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }

src/OpenIddict.Server/OpenIddictServerEvents.Protection.cs

@@ -26,7 +26,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it is not available.
+        /// Gets or sets the request, or <see langword="null"/> if it is not available.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -97,7 +97,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it is not available.
+        /// Gets or sets the request, or <see langword="null"/> if it is not available.
         /// </summary>
         public OpenIddictRequest? Request
         {

src/OpenIddict.Server/OpenIddictServerEvents.Revocation.cs

@@ -25,7 +25,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -59,7 +59,7 @@ public static partial class OpenIddictServerEvents
 
         /// <summary>
         /// Gets the optional token_type_hint parameter extracted from the
-        /// revocation request, or <c>null</c> if it cannot be found.
+        /// revocation request, or <see langword="null"/> if it cannot be found.
         /// </summary>
         public string? TokenTypeHint => Request.TokenTypeHint;
 
@@ -112,7 +112,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -132,7 +132,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }

src/OpenIddict.Server/OpenIddictServerEvents.Session.cs

@@ -23,7 +23,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -147,7 +147,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -167,7 +167,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
 

src/OpenIddict.Server/OpenIddictServerEvents.Userinfo.cs

@@ -26,7 +26,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the request, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -200,7 +200,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -220,7 +220,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets the error code returned to the client application.
         /// When the response indicates a successful response,
-        /// this property returns <c>null</c>.
+        /// this property returns <see langword="null"/>.
         /// </summary>
         public string? Error => Response.Error;
     }

src/OpenIddict.Server/OpenIddictServerEvents.cs

@@ -196,7 +196,7 @@ public static partial class OpenIddictServerEvents
         public ClaimsPrincipal? Principal { get; set; }
 
         /// <summary>
-        /// Gets the client identifier, or <c>null</c> if the client application is unknown.
+        /// Gets the client identifier, or <see langword="null"/> if the client application is unknown.
         /// </summary>
         public string? ClientId => Transaction.Request?.ClientId;
     }
@@ -229,7 +229,7 @@ public static partial class OpenIddictServerEvents
         }
 
         /// <summary>
-        /// Gets or sets the request or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {
@@ -705,7 +705,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets or sets the generated access token, if applicable.
         /// The access token will only be returned if
-        /// <see cref="IncludeAccessToken"/> is set to <c>true</c>.
+        /// <see cref="IncludeAccessToken"/> is set to <see langword="true"/>.
         /// </summary>
         public string? AccessToken { get; set; }
 
@@ -718,7 +718,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets or sets the generated authorization code, if applicable.
         /// The authorization code will only be returned if
-        /// <see cref="IncludeAuthorizationCode"/> is set to <c>true</c>.
+        /// <see cref="IncludeAuthorizationCode"/> is set to <see langword="true"/>.
         /// </summary>
         public string? AuthorizationCode { get; set; }
 
@@ -731,7 +731,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets or sets the generated device code, if applicable.
         /// The device code will only be returned if
-        /// <see cref="IncludeDeviceCode"/> is set to <c>true</c>.
+        /// <see cref="IncludeDeviceCode"/> is set to <see langword="true"/>.
         /// </summary>
         public string? DeviceCode { get; set; }
 
@@ -744,7 +744,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets or sets the generated identity token, if applicable.
         /// The identity token will only be returned if
-        /// <see cref="IncludeIdentityToken"/> is set to <c>true</c>.
+        /// <see cref="IncludeIdentityToken"/> is set to <see langword="true"/>.
         /// </summary>
         public string? IdentityToken { get; set; }
 
@@ -757,7 +757,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets or sets the generated refresh token, if applicable.
         /// The refresh token will only be returned if
-        /// <see cref="IncludeRefreshToken"/> is set to <c>true</c>.
+        /// <see cref="IncludeRefreshToken"/> is set to <see langword="true"/>.
         /// </summary>
         public string? RefreshToken { get; set; }
 
@@ -770,7 +770,7 @@ public static partial class OpenIddictServerEvents
         /// <summary>
         /// Gets or sets the generated user code, if applicable.
         /// The user code will only be returned if
-        /// <see cref="IncludeUserCode"/> is set to <c>true</c>.
+        /// <see cref="IncludeUserCode"/> is set to <see langword="true"/>.
         /// </summary>
         public string? UserCode { get; set; }
 

src/OpenIddict.Server/OpenIddictServerHelpers.cs

@@ -17,7 +17,7 @@ public static class OpenIddictServerHelpers
     /// <typeparam name="TProperty">The type of the property.</typeparam>
     /// <param name="transaction">The server transaction.</param>
     /// <param name="name">The property name.</param>
-    /// <returns>The property value or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The property value or <see langword="null"/> if it couldn't be found.</returns>
     public static TProperty? GetProperty<TProperty>(
         this OpenIddictServerTransaction transaction!!, string name) where TProperty : class
     {

src/OpenIddict.Validation.AspNetCore/OpenIddictValidationAspNetCoreHelpers.cs

@@ -18,7 +18,7 @@ public static class OpenIddictValidationAspNetCoreHelpers
     /// Retrieves the <see cref="HttpRequest"/> instance stored in the <see cref="OpenIddictValidationTransaction"/> properties.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpRequest? GetHttpRequest(this OpenIddictValidationTransaction transaction!!)
     {
         if (!transaction.Properties.TryGetValue(typeof(HttpRequest).FullName!, out object? property))
@@ -48,7 +48,7 @@ public static class OpenIddictValidationAspNetCoreHelpers
     /// Retrieves the <see cref="OpenIddictRequest"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictRequest? GetOpenIddictValidationRequest(this HttpContext context!!)
     {
         return context.Features.Get<OpenIddictValidationAspNetCoreFeature>()?.Transaction?.Request;
@@ -58,7 +58,7 @@ public static class OpenIddictValidationAspNetCoreHelpers
     /// Retrieves the <see cref="OpenIddictResponse"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictResponse"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictResponse"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictResponse? GetOpenIddictValidationResponse(this HttpContext context!!)
     {
         return context.Features.Get<OpenIddictValidationAspNetCoreFeature>()?.Transaction?.Response;

src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionOptions.cs

@@ -17,7 +17,7 @@ public class OpenIddictValidationDataProtectionOptions
     /// <summary>
     /// Gets or sets the data protection provider used to create the default
     /// data protectors used by the OpenIddict Data Protection validation services.
-    /// When this property is set to <c>null</c>, the data protection provider
+    /// When this property is set to <see langword="null"/>, the data protection provider
     /// is directly retrieved from the dependency injection container.
     /// </summary>
     public IDataProtectionProvider DataProtectionProvider { get; set; } = default!;

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinHelpers.cs

@@ -28,7 +28,7 @@ public static class OpenIddictValidationOwinHelpers
     /// Retrieves the <see cref="IOwinRequest"/> instance stored in the <see cref="OpenIddictValidationTransaction"/> properties.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="IOwinRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="IOwinRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static IOwinRequest? GetOwinRequest(this OpenIddictValidationTransaction transaction!!)
     {
         if (!transaction.Properties.TryGetValue(typeof(IOwinRequest).FullName!, out object? property))
@@ -56,7 +56,7 @@ public static class OpenIddictValidationOwinHelpers
     /// Retrieves the <see cref="OpenIddictRequest"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictRequest"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictRequest"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictRequest? GetOpenIddictValidationRequest(this IOwinContext context!!)
         => context.Get<OpenIddictValidationTransaction>(typeof(OpenIddictValidationTransaction).FullName)?.Request;
 
@@ -64,7 +64,7 @@ public static class OpenIddictValidationOwinHelpers
     /// Retrieves the <see cref="OpenIddictResponse"/> instance stored in <see cref="BaseContext"/>.
     /// </summary>
     /// <param name="context">The context instance.</param>
-    /// <returns>The <see cref="OpenIddictResponse"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="OpenIddictResponse"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static OpenIddictResponse? GetOpenIddictValidationResponse(this IOwinContext context!!)
         => context.Get<OpenIddictValidationTransaction>(typeof(OpenIddictValidationTransaction).FullName)?.Response;
 }

src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpHelpers.cs

@@ -17,7 +17,7 @@ public static class OpenIddictValidationSystemNetHttpHelpers
     /// Gets the <see cref="HttpRequestMessage"/> associated with the current context.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpRequestMessage"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpRequestMessage"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpRequestMessage? GetHttpRequestMessage(this OpenIddictValidationTransaction transaction)
         => transaction.GetProperty<HttpRequestMessage>(typeof(HttpRequestMessage).FullName!);
 
@@ -25,7 +25,7 @@ public static class OpenIddictValidationSystemNetHttpHelpers
     /// Gets the <see cref="HttpResponseMessage"/> associated with the current context.
     /// </summary>
     /// <param name="transaction">The transaction instance.</param>
-    /// <returns>The <see cref="HttpResponseMessage"/> instance or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The <see cref="HttpResponseMessage"/> instance or <see langword="null"/> if it couldn't be found.</returns>
     public static HttpResponseMessage? GetHttpResponseMessage(this OpenIddictValidationTransaction transaction)
         => transaction.GetProperty<HttpResponseMessage>(typeof(HttpResponseMessage).FullName!);
 }

src/OpenIddict.Validation/OpenIddictValidationBuilder.cs

@@ -121,7 +121,7 @@ public class OpenIddictValidationBuilder
     {
         // If the encryption key is an asymmetric security key, ensure it has a private key.
         if (key is AsymmetricSecurityKey asymmetricSecurityKey &&
-            asymmetricSecurityKey.PrivateKeyStatus == PrivateKeyStatus.DoesNotExist)
+            asymmetricSecurityKey.PrivateKeyStatus is PrivateKeyStatus.DoesNotExist)
         {
             throw new InvalidOperationException(SR.GetResourceString(SR.ID0055));
         }

src/OpenIddict.Validation/OpenIddictValidationEvents.Discovery.cs

@@ -82,7 +82,7 @@ public static partial class OpenIddictValidationEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {
@@ -200,7 +200,7 @@ public static partial class OpenIddictValidationEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {

src/OpenIddict.Validation/OpenIddictValidationEvents.Introspection.cs

@@ -92,7 +92,7 @@ public static partial class OpenIddictValidationEvents
         }
 
         /// <summary>
-        /// Gets or sets the response, or <c>null</c> if it wasn't extracted yet.
+        /// Gets or sets the response, or <see langword="null"/> if it wasn't extracted yet.
         /// </summary>
         public OpenIddictResponse? Response
         {

src/OpenIddict.Validation/OpenIddictValidationEvents.Protection.cs

@@ -26,7 +26,7 @@ public static partial class OpenIddictValidationEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it is not available.
+        /// Gets or sets the request, or <see langword="null"/> if it is not available.
         /// </summary>
         public OpenIddictRequest? Request
         {

src/OpenIddict.Validation/OpenIddictValidationEvents.cs

@@ -195,7 +195,7 @@ public static partial class OpenIddictValidationEvents
         }
 
         /// <summary>
-        /// Gets or sets the request, or <c>null</c> if it couldn't be extracted.
+        /// Gets or sets the request, or <see langword="null"/> if it couldn't be extracted.
         /// </summary>
         public OpenIddictRequest? Request
         {

src/OpenIddict.Validation/OpenIddictValidationHelpers.cs

@@ -17,7 +17,7 @@ public static class OpenIddictValidationHelpers
     /// <typeparam name="TProperty">The type of the property.</typeparam>
     /// <param name="transaction">The validation transaction.</param>
     /// <param name="name">The property name.</param>
-    /// <returns>The property value or <c>null</c> if it couldn't be found.</returns>
+    /// <returns>The property value or <see langword="null"/> if it couldn't be found.</returns>
     public static TProperty? GetProperty<TProperty>(
         this OpenIddictValidationTransaction transaction!!, string name) where TProperty : class
     {