diff --git a/lib/c/2014/labcomm_private.h b/lib/c/2014/labcomm_private.h
index 5047d658a4b55c2ba0d89a44ee3de0fb0e636ebc..1cef97dc4cec3abc311e040517d189b2aa10a6e3 100644
--- a/lib/c/2014/labcomm_private.h
+++ b/lib/c/2014/labcomm_private.h
@@ -64,6 +64,7 @@
 #define LABCOMM_FLOAT        0x25
 #define LABCOMM_DOUBLE       0x26
 #define LABCOMM_STRING       0x27
+#define LABCOMM_REF          0x28
 
 /* 
  * other special values