DOCSP-4588: some 4.0 tls/ssl cleanup

Author: kay-kim

source/tutorial/configure-ssl-clients.txt

@@ -89,6 +89,8 @@ certificate presented by the :binary:`~bin.mongod` or
   :option:`--host <mongo --host>` option or use a :doc:`connection
   string </reference/connection-string>`.
 
+.. _ssl-client-connection-only:
+
 Connect to MongoDB Instance Using Encryption
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -119,6 +121,8 @@ The :binary:`~bin.mongo` shell verifies the certificate presented by
 the :binary:`~bin.mongod` instance against the specified hostname and
 the CA file.
 
+.. _mongo-connect-require-client-certificates-ssl:
+
 Connect to MongoDB Instance that Requires Client Certificates
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~