--- openflow-2014-12-11-4.h	2015-07-23 09:54:18.092479401 -0700
+++ openflow-2015-01-13.h	2015-07-23 09:54:18.096479401 -0700
@@ -223,7 +223,7 @@
     OFPC_FRAG_NORMAL   = 0,       /* No special handling for fragments. */
     OFPC_FRAG_DROP     = 1 << 0,  /* Drop fragments. */
     OFPC_FRAG_REASM    = 1 << 1,  /* Reassemble (only if OFPC_IP_REASM set). */
-    OFPC_FRAG_MASK     = 3,
+    OFPC_FRAG_MASK     = 3,       /* Bitmask of flags dealing with frag. */
 };
 
 /* Switch configuration. */