Update AbpIdentityResultExtensions.cs

modules/identity/src/Volo.Abp.Identity.Domain/Microsoft/AspNetCore/Identity/AbpIdentityResultExtensions.cs

@@ -41,6 +41,7 @@ public static class AbpIdentityResultExtensions
 
         if (IdentityStrings.ContainsKey("InvalidUserName"))
         {
+            // The default text of `InvalidUserName` is `Username '{0}' is invalid, can only contain letters or digits.`
             IdentityStrings["InvalidUserName"] = "Username '{0}' is invalid.";
         }