Update index.md

docs/en/framework/architecture/multi-tenancy/index.md

@@ -391,7 +391,7 @@ Configure<AbpTenantResolveOptions>(options =>
 });
 ```
 
-This option can be helpful on development time or some specific scenarios to set a constant tenant for the application. It is a simple and consistent way to ensure that a tenant context is always available when needed. However, when you do that, no way to switch to the host side. It is not something you will need it most of the time, but here if you need such a resolution logic.
+The `FallbackTenant` value can be a tenant name or tenant's Id. This option can be helpful on development time or some specific scenarios to set a constant tenant for the application. It is a simple and consistent way to ensure that a tenant context is always available when needed. However, when you do that, no way to switch to the host side. It is not something you will need it most of the time, but here if you need such a resolution logic.
 
 #### Multi-Tenancy Middleware