Added RequiresUnreferencedCodeAttribute for frameworks other than NET50 and greater.

Core/BkwdComp/RequiresUnreferencedCode.cs

@@ -0,0 +1,26 @@
+#if !NET5_0_OR_GREATER
+
+namespace System.Diagnostics.CodeAnalysis;
+
+/// <summary>
+/// Indicates that the specified method requires dynamic access to code that is not referenced statically, for example, through <see cref="System.Reflection"/>.
+/// </summary>
+/// <seealso cref="Attribute"/>
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Constructor | AttributeTargets.Method, Inherited = false)]
+public sealed class RequiresUnreferencedCodeAttribute : Attribute
+{
+	/// <summary>Initializes a new instance of the <see cref="RequiresUnreferencedCodeAttribute"/> class with the specified message.</summary>
+	/// <param name="message">A message that contains information about the usage of unreferenced code.</param>
+	public RequiresUnreferencedCodeAttribute(string message) => Message = message;
+
+	/// <summary>Gets a message that contains information about the usage of unreferenced code.</summary>
+	public string Message { get; private set; }
+
+	/// <summary>
+	/// Gets or sets an optional URL that contains more information about the method, why it requires unreferenced code, and what options a
+	/// consumer has to deal with it.
+	/// </summary>
+	public string Url { get; set; }
+}
+
+#endif

Core/Vanara.Core.csproj

@@ -53,7 +53,4 @@ CorrespondingAction, FileAttributeConstant, FileOpConstant, FilePermissionConsta
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>
     </EmbeddedResource>
   </ItemGroup>
-  <ItemGroup>
-    <Folder Include="BkwdComp\" />
-  </ItemGroup>
 </Project>