Index: generic/nsf.tcl
===================================================================
diff -u -ra5e4ab3a3f85b51e855adb3fe981833c2534ee8b -r756a5ed4e51921ada898fdf69cc7bd2c5c616828
--- generic/nsf.tcl	(.../nsf.tcl)	(revision a5e4ab3a3f85b51e855adb3fe981833c2534ee8b)
+++ generic/nsf.tcl	(.../nsf.tcl)	(revision 756a5ed4e51921ada898fdf69cc7bd2c5c616828)
@@ -79,7 +79,23 @@
   ::nsf::method::provide autoname {::nsf::method::alias autoname ::nsf::methods::object::autoname}
   ::nsf::method::provide exists   {::nsf::method::alias exists   ::nsf::methods::object::exists}
 
+  ######################################################################
+  # unknown handler for objects and classes
   #
+  proc ::nsf::unknown {name} {
+    foreach {key handler} [array get ::nsf::unknown] {
+      set result [uplevel [list {*}$handler $name]]
+      if {$result ne ""} {
+	return $result
+      }
+    }
+    return ""
+  }
+  # Example unknown handler:
+  # set ::nsf::unknown(xotcl) {::xotcl::Class __unknown}
+
+
+  ######################################################################
   # exit handlers
   #
   proc ::nsf::exithandler {args} {