netcoreapp3.1 
namespace System.Web
{
    [Flags]
    public enum RequestNotification
    {
        ReleaseRequestState = 256
    }
}
.NET
5.06.07.08.09.010.0
.NET Core
2.02.12.23.03.1
.NET Framework
2.03.03.54.04.54.5.14.5.24.64.6.14.6.24.74.7.14.7.24.84.8.1
.NET Standard
2.02.1
Information specific to netcoreapp3.1
Assembly

Microsoft.AspNetCore.SystemWebAdapters , Version=2.0.0.0, PublicKeyToken=adb9793829ddae60

Referencing

Your project needs a package reference to Microsoft.AspNetCore.SystemWebAdapters.

Package Microsoft.AspNetCore.SystemWebAdapters (2.0.0) netstandard2.0
Platform Restrictions

This framework does not have platform annotations.

  • Built-in API
  • Package-provided API