comment the VCL for clarity

doc/sphinx/users-guide/purging.rst

@@ -39,6 +39,7 @@ following VCL in place::
 		  if (!client.ip ~ purge) {
 			  error 405 "Not allowed.";
 		  }
+                  # jump to hit/miss
 		  return (lookup);
 	  }
   }
@@ -133,7 +134,7 @@ object is not available in the ban lurker thread.
 
 You can use the following template to write ban lurker friendly bans::
 
-  sub vcl_fetch {
+  sub vcl_backend_response {
     set beresp.http.x-url = req.url;
   }