diff --git a/config.py b/config.py
index 1a8f0b3..dfec6e7 100644
--- a/config.py
+++ b/config.py
@@ -25,7 +25,7 @@ from error import (HiddenOptionError, ConfigError, NotFoundError,
                             SpecialOwnersError, MandatoryError, MethodCallError, 
                                            DisabledOptionError, ModeOptionError)
 from option import (OptionDescription, Option, SymLinkOption, group_types, 
-                                                   Multi, apply_requires, modes)
+                    default_owner ,Multi, apply_requires, modes)
 import autolib
 from autolib import special_owners, special_owner_factory
 # ____________________________________________________________
@@ -34,7 +34,7 @@ class Config(object):
     _cfgimpl_disabled = True
     _cfgimpl_mandatory = True
     _cfgimpl_frozen = False
-    _cfgimpl_owner = "user"
+    _cfgimpl_owner = default_owner
     _cfgimpl_toplevel = None
     _cfgimpl_mode = 'normal'
     
@@ -66,13 +66,14 @@ class Config(object):
         for child in self._cfgimpl_descr._children:
             if isinstance(child, Option):
                 if child.is_multi():
-                    mm = Multi(child.getdefault())
-                    self._cfgimpl_values[child._name] = mm
-                    self._cfgimpl_previous_values[child._name] = mm
+                    childdef = Multi(child.getdefault(), config=self, 
+                                     child=child)
+                    self._cfgimpl_values[child._name] = childdef
+                    self._cfgimpl_previous_values[child._name] = childdef
                 else:
-                    dd = child.getdefault()
-                    self._cfgimpl_values[child._name] = dd
-                    self._cfgimpl_previous_values[child._name] = dd 
+                    childdef = child.getdefault()
+                    self._cfgimpl_values[child._name] = childdef
+                    self._cfgimpl_previous_values[child._name] = childdef 
                 if child.getcallback() is not None:
                     if child._is_hidden():
                         self._cfgimpl_value_owners[child._name] = 'auto'
diff --git a/option.py b/option.py
index 4105420..7e7fc16 100644
--- a/option.py
+++ b/option.py
@@ -28,21 +28,44 @@ available_actions = ['hide', 'show', 'enable', 'disable']
 reverse_actions = {'hide': 'show', 'show': 'hide', 
                    'disable':'enable', 'enable': 'disable'}
 # ____________________________________________________________
+# generic owner. 'default' is the general config owner after init time
+default_owner = 'user'
 # OptionDescription authorized group_type values
 group_types = ['default', 'family', 'group', 'master']
 # multi types 
 class Multi(list):
-    "wrapper for list (multi) option types"
+    "container that support items for the values of list (multi) options" 
+    def __init__(self, lst, config=None, child=None):
+        self.config = config
+        self.child = child
+        super(Multi, self).__init__(lst)
+        
     def __getitem__(self, key):
-        # FIXME test if None, etc...
-        return super(Multi, self).__getitem__(key)
-#        return list.__getitem__(self, key)
-
+        value =  super(Multi, self).__getitem__(key)
+        if value is None:
+            return self.child.default_multi
+            
     def __setitem__(self, key, value):
-        # FIXME  do some stuff here
+        if value != None and not self.child._validate(value):
+            raise ConfigError("invalid value {0} "
+                "for option {1}".format(str(value), self.child._name))
+        # FIXME : and if value is None ???
         return super(Multi, self).__setitem__(key, value)
-# ____________________________________________________________
 
+    def append(self, value, owner=default_owner):
+        if owner is None:
+            owner = 'default'
+        self.child.setowner(self.config, owner)
+        # changer dans la config la valeur par défaut et le owner
+        if value != None and not self.child._validate(value):
+            raise ConfigError("invalid value {0} "
+                "for option {1}".format(str(value), self.child._name))
+        self.config._cfgimpl_values[child._name].append(value)
+    
+#    def pop(self):
+#        pass 
+# ____________________________________________________________
+#
 class Option(HiddenBaseType, DisabledBaseType, ModeBaseType):
     #reminder: an Option object is **not** a container for the value
     _frozen = False