note about token format

lib/cartodb/server.js

@@ -579,6 +579,8 @@ module.exports = function(serverOptions) {
         var user = cdbRequest.userByReq(req);
 
         if ( req.params.token ) {
+            // Token might match the following patterns:
+            // - {user}@{tpl_id}@{token}:{cache_buster}
             //console.log("Request parameters include token " + req.params.token);
             var tksplit = req.params.token.split(':');
             req.params.token = tksplit[0];