diff --git a/application/helpers/expressions/em_core_helper.php b/application/helpers/expressions/em_core_helper.php
index 46b32e0ec25..f847d60f5d8 100644
--- a/application/helpers/expressions/em_core_helper.php
+++ b/application/helpers/expressions/em_core_helper.php
@@ -39,20 +39,23 @@ class ExpressionManager
         'valueNAOK',
         'value',
     );
-    // These are the allowable static suffixes for variables - each represents an attribute of a variable that can not be updated on same page
+    /* var string[] allowable static suffixes for variables - each represents an attribute of a variable that can not be updated on same page
+     * @see LimeExpressionManager->knownVars definition
+     */
     private $aRDP_regexpStaticAttribute = array(
+        'qid',
         'gid',
+        'question',
+        'sgqa',
+        'type',
+        'relevance',
         'grelevance',
+        'qseq',
         'gseq',
         'jsName',
+        'jsName_on',
         'mandatory',
-        'qid',
-        'qseq',
-        'question',
-        'relevance',
         'rowdivid',
-        'sgqa',
-        'type',
     );
     // These three variables are effectively static once constructed
     private $RDP_ExpressionRegex;