diff -r 736bf7117153 -r 793766d4c1b5 src/Pure/General/markup.scala
--- a/src/Pure/General/markup.scala	Fri Jan 16 22:54:11 2009 +0100
+++ b/src/Pure/General/markup.scala	Fri Jan 16 22:56:12 2009 +0100
@@ -131,6 +131,21 @@
   val SESSION = "session"
 
   val MESSAGE = "message"
+  val CLASS = "class"
+
+  val INIT = "init"
+  val STATUS = "status"
+  val WRITELN = "writeln"
+  val PRIORITY = "priority"
+  val TRACING = "tracing"
+  val WARNING = "warning"
+  val ERROR = "error"
+  val DEBUG = "debug"
+  val SYSTEM = "system"
+  val STDIN = "stdin"
+  val STDOUT = "stdout"
+  val SIGNAL = "signal"
+  val EXIT = "exit"
 
 
   /* content */