Index: generic/xotclInt.h
===================================================================
diff -u -r543e283a1681f4e7075eb65a0dd97f54cf48e2f7 -rf79e2c8697d6f0ae0082c257a65240e815e99ad8
--- generic/xotclInt.h	(.../xotclInt.h)	(revision 543e283a1681f4e7075eb65a0dd97f54cf48e2f7)
+++ generic/xotclInt.h	(.../xotclInt.h)	(revision f79e2c8697d6f0ae0082c257a65240e815e99ad8)
@@ -424,6 +424,11 @@
 #define XOTCL_DELETED                        0x4000
 #define XOTCL_RECREATE                       0x8000
 
+/* flags for argDefinitions */
+
+#define XOTCL_ARG_REQUIRED		     0x0001
+#define XOTCL_ARG_SUBST_DEFAULT		     0x0002
+
 #define XOTclObjectSetClass(obj) \
 	(obj)->flags |= XOTCL_IS_CLASS
 #define XOTclObjectClearClass(obj) \
@@ -442,7 +447,7 @@
 
 typedef struct  {
   char *name;
-  int required;
+  int flags;
   int nrargs;
   XOTclTypeConverter *converter;
   Tcl_Obj *defaultValue;