diff -r 57a41389d0e2 -r 3235ecdcd884 src/Pure/PIDE/markup.scala
--- a/src/Pure/PIDE/markup.scala	Fri Mar 15 22:02:05 2019 +0100
+++ b/src/Pure/PIDE/markup.scala	Sun Mar 17 20:03:55 2019 +0100
@@ -96,6 +96,7 @@
   val META_CONTRIBUTOR = "meta_contributor"
   val META_DATE = "meta_date"
   val META_DESCRIPTION = "meta_description"
+  val META_LICENSE = "meta_license"
 
 
   /* formal entities */