--- openflow-2012-01-09-2.h	2015-07-23 09:54:16.876479351 -0700
+++ openflow-2012-01-11.h	2015-07-23 09:54:16.880479351 -0700
@@ -853,8 +853,8 @@
     OFPAT_SET_NW_TTL   = 23, /* IP TTL. */
     OFPAT_DEC_NW_TTL   = 24, /* Decrement IP TTL. */
     OFPAT_SET_FIELD    = 25, /* Set a header field using OXM TLV format. */
-    OFPAT_PUSH_PBB     = 26, /* Push a new PBB service tag */
-    OFPAT_POP_PBB      = 27, /* Pop the outer PBB service tag */
+    OFPAT_PUSH_PBB     = 26, /* Push a new PBB service tag (I-TAG) */
+    OFPAT_POP_PBB      = 27, /* Pop the outer PBB service tag (I-TAG) */
     OFPAT_EXPERIMENTER = 0xffff
 };