obsoletion of TSL 1.0 and 1.1 (#7845)

Author: gewarren

xml/System.Security.Authentication/SslProtocols.xml

@@ -276,7 +276,7 @@
       </ReturnValue>
       <MemberValue>192</MemberValue>
       <Docs>
-        <summary>Specifies the TLS 1.0 security protocol.  TLS 1.0 is provided for backward compatibility only. The TLS protocol is defined in IETF RFC 2246.</summary>
+        <summary>Specifies the TLS 1.0 security protocol. TLS 1.0 is provided for backward compatibility only. The TLS protocol is defined in IETF RFC 2246. This field is obsolete starting in .NET 7.</summary>
       </Docs>
     </Member>
     <Member MemberName="Tls11">
@@ -318,7 +318,7 @@
       </ReturnValue>
       <MemberValue>768</MemberValue>
       <Docs>
-        <summary>Specifies the TLS 1.1 security protocol. The TLS protocol is defined in IETF RFC 4346.</summary>
+        <summary>Specifies the TLS 1.1 security protocol. The TLS protocol is defined in IETF RFC 4346. This field is obsolete starting in .NET 7.</summary>
       </Docs>
     </Member>
     <Member MemberName="Tls12">