--- a/stage1_2/iec_flex.ll	Mon Feb 24 22:00:55 2014 +0000
+++ b/stage1_2/iec_flex.ll	Sun Mar 02 16:42:56 2014 +0000
@@ -1245,6 +1245,8 @@
 	/******************************************************/
 
 
+REF	{if (get_opt_ref_operator()) return REF; else unput(0);}		/* Keyword in IEC 61131-3 v3 */
+
 EN	return EN;			/* Keyword */
 ENO	return ENO;			/* Keyword */