Index: src/wp-includes/class-wp-xmlrpc-server.php
===================================================================
--- src/wp-includes/class-wp-xmlrpc-server.php	(revision 37024)
+++ src/wp-includes/class-wp-xmlrpc-server.php	(working copy)
@@ -247,10 +247,23 @@
 		}
 
 		/**
-		 * Filter whether XML-RPC is enabled.
+		 * Filter whether XML-RPC methods requiring authentication are enabled.
 		 *
-		 * This is the proper filter for turning off XML-RPC.
+		 * Contrary to the way it's named, this filter does not control whether XML-RPC is *fully*
+		 * enabled, rather, it only controls whether XML-RPC methods requiring authentication - such
+		 * as for publishing purposes - are enabled.
 		 *
+		 * Further, the filter does not control whether pingbacks or other custom endpoints that don't
+		 * require authentication are enabled. This behavior is expected, and due to how parity was matched
+		 * with the `enable_xmlrpc` UI option the filter replaced when it was introduced in 3.5.
+		 *
+		 * To disable XML-RPC methods that require authentication, use:
+		 *
+		 *     add_filter( 'xmlrpc_enabled', '__return_false' );
+		 *
+		 * For more granular control over all XML-RPC methods and requests, see the {@see 'xmlrpc_methods'}
+		 * and {@see 'xmlrpc_element_limit'} hooks.
+		 *
 		 * @since 3.5.0
 		 *
 		 * @param bool $enabled Whether XML-RPC is enabled. Default true.