diff -r 9210cf2b4869 -r 1261481ef5e5 src/Pure/General/markup.scala
--- a/src/Pure/General/markup.scala	Tue Aug 31 22:03:55 2010 +0200
+++ b/src/Pure/General/markup.scala	Tue Aug 31 23:28:21 2010 +0200
@@ -69,6 +69,7 @@
 
   /* formal entities */
 
+  val BINDING = "binding"
   val ENTITY = "entity"
   val DEF = "def"
   val REF = "ref"