--- src/sys/sys/varsym.h	2003/11/09 20:29:57	1.2
+++ src/sys/sys/varsym.h	2005/01/14 02:25:08	1.3
@@ -40,6 +40,7 @@ struct varsymset {
 #define VARSYM_PROC	1
 #define VARSYM_USER	2
 #define VARSYM_SYS	3
+#define VARSYM_PRISON	4	/* used internally */
 
 #define VARSYM_PROC_MASK	(1 << VARSYM_PROC)
 #define VARSYM_USER_MASK	(1 << VARSYM_USER)