Index: generic/predefined.h
===================================================================
diff -u -r48d5751e9aeb6a4f388f6531a9248c1847b22cae -rf4e75c452cf99c87ad8705c954cb9548652873fa
--- generic/predefined.h	(.../predefined.h)	(revision 48d5751e9aeb6a4f388f6531a9248c1847b22cae)
+++ generic/predefined.h	(.../predefined.h)	(revision f4e75c452cf99c87ad8705c954cb9548652873fa)
@@ -412,11 +412,11 @@
 "\\[list [::xotcl::self] __value_changed_cmd \\[::xotcl::self\\] [list [set :valuechangedcmd]]\\]\"}\n"
 "if {$__initcmd ne \"\"} {\n"
 "set :initcmd $__initcmd}}\n"
-"::xotcl2::Class create ::xotcl::ObjectParameterSlot::Nocheck {\n"
+"::xotcl2::Class create ::xotcl::Attribute::Nocheck {\n"
 ":method check_single_value args {;}\n"
 ":method check_multiple_values args {;}\n"
 ":method mk_type_checker args {return \"\"}}\n"
-"::xotcl2::Class create ::xotcl::ObjectParameterSlot::Optimizer {\n"
+"::xotcl2::Class create ::xotcl::Attribute::Optimizer {\n"
 ":method method args  {::xotcl::next; :optimize}\n"
 ":method forward args {::xotcl::next; :optimize}\n"
 ":protected method init args    {::xotcl::next; :optimize}\n"
@@ -426,7 +426,7 @@
 "if {[:info callable -which assign] ne \"::xotcl::ObjectParameterSlot alias assign ::xotcl::setinstvar\"} return\n"
 "if {[:info callable -which get]    ne \"::xotcl::ObjectParameterSlot alias get ::xotcl::setinstvar\"} return\n"
 "::xotcl::setter ${:domain} {*}[expr {${:per-object} ? \"-per-object\" : \"\"}] ${:name}}}\n"
-"::xotcl::Attribute mixin add ::xotcl::ObjectParameterSlot::Optimizer\n"
+"::xotcl::Attribute mixin add ::xotcl::Attribute::Optimizer\n"
 "::xotcl2::Class public method parameter arglist {\n"
 "if {![::xotcl::is [::xotcl::self]::slot object]} {\n"
 "::xotcl2::Object create [::xotcl::self]::slot}\n"
Index: generic/predefined.xotcl
===================================================================
diff -u -r48d5751e9aeb6a4f388f6531a9248c1847b22cae -rf4e75c452cf99c87ad8705c954cb9548652873fa
--- generic/predefined.xotcl	(.../predefined.xotcl)	(revision 48d5751e9aeb6a4f388f6531a9248c1847b22cae)
+++ generic/predefined.xotcl	(.../predefined.xotcl)	(revision f4e75c452cf99c87ad8705c954cb9548652873fa)
@@ -784,13 +784,13 @@
   }
   
   # mixin class for decativating all value checks in slots
-  ::xotcl2::Class create ::xotcl::ObjectParameterSlot::Nocheck {
+  ::xotcl2::Class create ::xotcl::Attribute::Nocheck {
     :method check_single_value args {;}
     :method check_multiple_values args {;}
     :method mk_type_checker args {return ""}
   }
   # mixin class for optimizing slots
-  ::xotcl2::Class create ::xotcl::ObjectParameterSlot::Optimizer {
+  ::xotcl2::Class create ::xotcl::Attribute::Optimizer {
     :method method args  {::xotcl::next; :optimize}
     :method forward args {::xotcl::next; :optimize}
     :protected method init args    {::xotcl::next; :optimize}
@@ -806,7 +806,7 @@
     }
   }
   # register the optimizer per default
-  ::xotcl::Attribute mixin add ::xotcl::ObjectParameterSlot::Optimizer
+  ::xotcl::Attribute mixin add ::xotcl::Attribute::Optimizer
 
 
   ############################################
Index: tests/slottest.xotcl
===================================================================
diff -u -r48d5751e9aeb6a4f388f6531a9248c1847b22cae -rf4e75c452cf99c87ad8705c954cb9548652873fa
--- tests/slottest.xotcl	(.../slottest.xotcl)	(revision 48d5751e9aeb6a4f388f6531a9248c1847b22cae)
+++ tests/slottest.xotcl	(.../slottest.xotcl)	(revision f4e75c452cf99c87ad8705c954cb9548652873fa)
@@ -251,7 +251,7 @@
 #   }
 # }
 
-::xotcl::Attribute mixin delete ::xotcl::ObjectParameterSlot::Optimizer
+::xotcl::Attribute mixin delete ::xotcl::Attribute::Optimizer
 
 Class C1 -parameter {a {b 10} {c "Hello World"}}
 C1 c1 -a 1
@@ -277,7 +277,7 @@
 ? {c2 a} 1 "new indirect parametercmd"
 ? {c2 a 1} 1 "new indirect parametercmd"
 
-::xotcl::ObjectParameterSlot mixin add ::xotcl::ObjectParameterSlot::Optimizer
+::xotcl::Attribute mixin add ::xotcl::Attribute::Optimizer
 
 Class C3 -slots {
   Attribute create a