diff --git a/doc/api/tiramisu.storage.txt b/doc/api/tiramisu.storage.txt
new file mode 100644
index 0000000..86cb062
--- /dev/null
+++ b/doc/api/tiramisu.storage.txt
@@ -0,0 +1,6 @@
+tiramisu.storage
+================
+
+.. automodule:: tiramisu.storage
+   :members:
+   :noindex:   
\ No newline at end of file
diff --git a/test/test_config.py b/test/test_config.py
index 17e863a..e091294 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -230,3 +230,9 @@ def test_duplicated_option():
     root = OptionDescription('root', '', [d1, d2])
     #in different OptionDescription
     raises(ConflictError, "config = Config(root)")
+
+def test_cannot_assign_value_to_option_description():
+    descr = make_description()
+    cfg = Config(descr)
+    raises(TypeError, "cfg.gc = 3")
+
diff --git a/test/test_config_ip.py b/test/test_config_ip.py
index 2bdba53..b7d3010 100644
--- a/test/test_config_ip.py
+++ b/test/test_config_ip.py
@@ -7,7 +7,7 @@ from tiramisu.option import IPOption, NetworkOption, NetmaskOption, \
 
 def test_ip():
     a = IPOption('a', '')
-    b = IPOption('b', '', only_private=True)
+    b = IPOption('b', '', private_only=True)
     od = OptionDescription('od', '', [a, b])
     c = Config(od)
     c.a = '192.168.1.1'
diff --git a/test/test_option_calculation.py b/test/test_option_calculation.py
index 8ca8687..117de9d 100644
--- a/test/test_option_calculation.py
+++ b/test/test_option_calculation.py
@@ -28,6 +28,12 @@ def return_value(value=None):
     return value
 
 
+def return_value2(*args, **kwargs):
+    value = list(args)
+    value.extend(kwargs.values())
+    return value
+
+
 def make_description():
     gcoption = ChoiceOption('name', 'GC name', ('ref', 'framework'), 'ref')
     gcdummy = BoolOption('dummy', 'dummy', default=False)
@@ -675,3 +681,13 @@ def test_callback_multi_multi():
     raises(ConfigError, "cfg.val4")
     assert cfg.val5 == ['val1', 'val4', 'val2', 'val4', 'val3', 'val4']
     assert cfg.val7 == ['val1', 'val21', 'val2', 'val22', 'val3', 'val23']
+
+
+def test_multi_with_no_value():
+    #First option return [] (so without value)
+    val1 = StrOption('val1', "", ['val'], multi=True)
+    val2 = StrOption('val2', "", multi=True)
+    val3 = StrOption('val3', '', multi=True, callback=return_value, callback_params={'': ((val2, False),), 'value': ((val1, False),)})
+    od = OptionDescription('od', '', [val1, val2, val3])
+    c = Config(od)
+    raises(ConfigError, "c.val3")
diff --git a/test/test_option_consistency.py b/test/test_option_consistency.py
index 5cf53cd..d5226db 100644
--- a/test/test_option_consistency.py
+++ b/test/test_option_consistency.py
@@ -4,7 +4,8 @@ from py.test import raises
 from tiramisu.setting import owners, groups
 from tiramisu.config import Config
 from tiramisu.option import IPOption, NetworkOption, NetmaskOption, IntOption,\
-    SymLinkOption, OptionDescription
+    BroadcastOption, SymLinkOption, OptionDescription
+from tiramisu.error import ConfigError
 
 
 def test_consistency_not_equal():
@@ -22,6 +23,60 @@ def test_consistency_not_equal():
     c.b = 2
 
 
+def test_consistency_not_equal_many_opts():
+    a = IntOption('a', '')
+    b = IntOption('b', '')
+    c = IntOption('c', '')
+    d = IntOption('d', '')
+    e = IntOption('e', '')
+    f = IntOption('f', '')
+    od = OptionDescription('od', '', [a, b, c, d, e, f])
+    a.impl_add_consistency('not_equal', b, c, d, e, f)
+    c = Config(od)
+    assert c.a is None
+    assert c.b is None
+    #
+    c.a = 1
+    del(c.a)
+    #
+    c.a = 1
+    raises(ValueError, "c.b = 1")
+    #
+    c.b = 2
+    raises(ValueError, "c.f = 2")
+    raises(ValueError, "c.f = 1")
+    #
+    c.d = 3
+    raises(ValueError, "c.f = 3")
+    raises(ValueError, "c.a = 3")
+    raises(ValueError, "c.c = 3")
+    raises(ValueError, "c.e = 3")
+
+
+def test_consistency_not_in_config():
+    a = IntOption('a', '')
+    b = IntOption('b', '')
+    a.impl_add_consistency('not_equal', b)
+    od1 = OptionDescription('od1', '', [a])
+    od2 = OptionDescription('od2', '', [b])
+    od = OptionDescription('root', '', [od1])
+    raises(ConfigError, "Config(od)")
+    od = OptionDescription('root', '', [od1, od2])
+    Config(od)
+    #with subconfig
+    raises(ConfigError, "Config(od.od1)")
+
+
+def test_consistency_afer_config():
+    a = IntOption('a', '')
+    b = IntOption('b', '')
+    od1 = OptionDescription('od1', '', [a])
+    od2 = OptionDescription('od2', '', [b])
+    od = OptionDescription('root', '', [od1, od2])
+    Config(od)
+    raises(AttributeError, "a.impl_add_consistency('not_equal', b)")
+
+
 def test_consistency_not_equal_symlink():
     a = IntOption('a', '')
     b = IntOption('b', '')
@@ -29,7 +84,7 @@ def test_consistency_not_equal_symlink():
     od = OptionDescription('od', '', [a, b, c])
     a.impl_add_consistency('not_equal', b)
     c = Config(od)
-    assert set(od._consistencies.keys()) == set([a, b])
+    assert set(od._cache_consistencies.keys()) == set([a, b])
 
 
 def test_consistency_not_equal_multi():
@@ -53,6 +108,14 @@ def test_consistency_default():
     raises(ValueError, "a.impl_add_consistency('not_equal', b)")
 
 
+def test_consistency_default_multi():
+    a = IntOption('a', '', [2, 1], multi=True)
+    b = IntOption('b', '', [1, 1], multi=True)
+    c = IntOption('c', '', [1, 2], multi=True)
+    raises(ValueError, "a.impl_add_consistency('not_equal', b)")
+    a.impl_add_consistency('not_equal', c)
+
+
 def test_consistency_default_diff():
     a = IntOption('a', '', 3)
     b = IntOption('b', '', 1)
@@ -99,7 +162,7 @@ def test_consistency_ip_netmask_error_multi():
     a = IPOption('a', '', multi=True)
     b = NetmaskOption('b', '')
     od = OptionDescription('od', '', [a, b])
-    raises(ValueError, "b.impl_add_consistency('ip_netmask', a)")
+    raises(ConfigError, "b.impl_add_consistency('ip_netmask', a)")
 
 
 def test_consistency_ip_netmask_multi():
@@ -159,3 +222,53 @@ def test_consistency_network_netmask_multi_master():
     c.a = ['192.168.1.0']
     c.b = ['255.255.255.0']
     raises(ValueError, "c.a = ['192.168.1.1']")
+
+
+def test_consistency_broadcast():
+    a = NetworkOption('a', '', multi=True)
+    b = NetmaskOption('b', '', multi=True)
+    c = BroadcastOption('c', '', multi=True)
+    od = OptionDescription('a', '', [a, b, c])
+    od.impl_set_group_type(groups.master)
+    b.impl_add_consistency('network_netmask', a)
+    c.impl_add_consistency('broadcast', a, b)
+    c = Config(od)
+    #first, test network_netmask
+    c.a = ['192.168.1.128']
+    raises(ValueError, "c.b = ['255.255.255.0']")
+    #
+    c.a = ['192.168.1.0']
+    c.b = ['255.255.255.0']
+    c.c = ['192.168.1.255']
+    raises(ValueError, "c.a = ['192.168.1.1']")
+    #
+    c.a = ['192.168.1.0', '192.168.2.128']
+    c.b = ['255.255.255.0', '255.255.255.128']
+    c.c = ['192.168.1.255', '192.168.2.255']
+    raises(ValueError, "c.c[1] = '192.168.2.128'")
+    c.c[1] = '192.168.2.255'
+
+
+def test_consistency_broadcast_default():
+    a = NetworkOption('a', '', '192.168.1.0')
+    b = NetmaskOption('b', '', '255.255.255.128')
+    c = BroadcastOption('c', '', '192.168.2.127')
+    d = BroadcastOption('d', '', '192.168.1.127')
+    od = OptionDescription('a', '', [a, b, c])
+    raises(ValueError, "c.impl_add_consistency('broadcast', a, b)")
+    od2 = OptionDescription('a', '', [a, b, d])
+    d.impl_add_consistency('broadcast', a, b)
+
+
+def test_consistency_not_all():
+    #_cache_consistencies is not None by not options has consistencies
+    a = NetworkOption('a', '', multi=True)
+    b = NetmaskOption('b', '', multi=True)
+    c = BroadcastOption('c', '', multi=True)
+    od = OptionDescription('a', '', [a, b, c])
+    od.impl_set_group_type(groups.master)
+    b.impl_add_consistency('network_netmask', a)
+    c = Config(od)
+    c.a = ['192.168.1.0']
+    c.b = ['255.255.255.0']
+    c.c = ['192.168.1.255']
diff --git a/test/test_option_validator.py b/test/test_option_validator.py
index 8e00916..001f9f7 100644
--- a/test/test_option_validator.py
+++ b/test/test_option_validator.py
@@ -1,9 +1,11 @@
 import autopath
+import warnings
 from py.test import raises
 
 from tiramisu.config import Config
 from tiramisu.option import StrOption, OptionDescription
-from tiramisu.error import ConfigError
+from tiramisu.setting import groups
+from tiramisu.error import ValueWarning
 
 
 def return_true(value, param=None):
@@ -13,37 +15,36 @@ def return_true(value, param=None):
 
 def return_false(value, param=None):
     if value == 'val' and param in [None, 'yes']:
-        return False
+        raise ValueError('error')
 
 
 def return_val(value, param=None):
     return 'val'
 
 
+def return_if_val(value):
+    if value != 'val':
+        raise ValueError('error')
+
+
 def test_validator():
     opt1 = StrOption('opt1', '', validator=return_true, default='val')
     raises(ValueError, "StrOption('opt2', '', validator=return_false, default='val')")
-    raises(ConfigError, "StrOption('opt3', '', validator=return_val, default='val')")
     opt2 = StrOption('opt2', '', validator=return_false)
-    opt3 = StrOption('opt3', '', validator=return_val)
-    root = OptionDescription('root', '', [opt1, opt2, opt3])
+    root = OptionDescription('root', '', [opt1, opt2])
     cfg = Config(root)
     assert cfg.opt1 == 'val'
     raises(ValueError, "cfg.opt2 = 'val'")
-    raises(ConfigError, "cfg.opt3 = 'val'")
 
 
 def test_validator_params():
     opt1 = StrOption('opt1', '', validator=return_true, validator_params={'': ('yes',)}, default='val')
     raises(ValueError, "StrOption('opt2', '', validator=return_false, validator_params={'': ('yes',)}, default='val')")
-    raises(ConfigError, "StrOption('opt3', '', validator=return_val, validator_params={'': ('yes',)}, default='val')")
     opt2 = StrOption('opt2', '', validator=return_false, validator_params={'': ('yes',)})
-    opt3 = StrOption('opt3', '', validator=return_val, validator_params={'': ('yes',)})
-    root = OptionDescription('root', '', [opt1, opt2, opt3])
+    root = OptionDescription('root', '', [opt1, opt2])
     cfg = Config(root)
     assert cfg.opt1 == 'val'
     raises(ValueError, "cfg.opt2 = 'val'")
-    raises(ConfigError, "cfg.opt3 = 'val'")
 
 
 def test_validator_params_key():
@@ -57,3 +58,98 @@ def test_validator_params_key():
 def test_validator_params_option():
     opt0 = StrOption('opt0', '', default='val')
     raises(ValueError, "opt1 = StrOption('opt1', '', validator=return_true, validator_params={'': ((opt0, False),)}, default='val')")
+
+
+def test_validator_multi():
+    opt1 = StrOption('opt1', '', validator=return_if_val, multi=True)
+    root = OptionDescription('root', '', [opt1])
+    cfg = Config(root)
+    assert cfg.opt1 == []
+    cfg.opt1.append('val')
+    assert cfg.opt1 == ['val']
+    raises(ValueError, "cfg.opt1.append('val1')")
+    raises(ValueError, "cfg.opt1 = ['val', 'val1']")
+
+
+def test_validator_warning():
+    opt1 = StrOption('opt1', '', validator=return_true, default='val', warnings_only=True)
+    opt2 = StrOption('opt2', '', validator=return_false, warnings_only=True)
+    opt3 = StrOption('opt3', '', validator=return_if_val, multi=True, warnings_only=True)
+    root = OptionDescription('root', '', [opt1, opt2, opt3])
+    cfg = Config(root)
+    assert cfg.opt1 == 'val'
+    warnings.simplefilter("always", ValueWarning)
+    with warnings.catch_warnings(record=True) as w:
+        cfg.opt1 = 'val'
+    assert w == []
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.opt2 = 'val'
+    assert len(w) == 1
+    assert w[0].message.opt == opt2
+    assert str(w[0].message) == 'invalid value val for option opt2: error'
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.opt3.append('val')
+    assert w == []
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.opt3.append('val1')
+    assert len(w) == 1
+    assert w[0].message.opt == opt3
+    assert str(w[0].message) == 'invalid value val1 for option opt3: error'
+    raises(ValueError, "cfg.opt2 = 1")
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.opt2 = 'val'
+        cfg.opt3.append('val')
+    assert len(w) == 2
+    assert w[0].message.opt == opt2
+    assert str(w[0].message) == 'invalid value val for option opt2: error'
+    assert w[1].message.opt == opt3
+    assert str(w[1].message) == 'invalid value val1 for option opt3: error'
+
+
+def test_validator_warning_master_slave():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip reseau autorise", multi=True, validator=return_false, warnings_only=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-reseau", multi=True, validator=return_if_val, warnings_only=True)
+    interface1 = OptionDescription('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    interface1.impl_set_group_type(groups.master)
+    assert interface1.impl_get_group_type() == groups.master
+    root = OptionDescription('root', '', [interface1])
+    cfg = Config(root)
+    warnings.simplefilter("always", ValueWarning)
+    with warnings.catch_warnings(record=True) as w:
+        cfg.ip_admin_eth0.ip_admin_eth0.append(None)
+    assert w == []
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.ip_admin_eth0.netmask_admin_eth0 = ['val1']
+    assert len(w) == 1
+    assert w[0].message.opt == netmask_admin_eth0
+    assert str(w[0].message) == 'invalid value val1 for option netmask_admin_eth0: error'
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.ip_admin_eth0.ip_admin_eth0 = ['val']
+    assert len(w) == 1
+    assert w[0].message.opt == ip_admin_eth0
+    assert str(w[0].message) == 'invalid value val for option ip_admin_eth0: error'
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.ip_admin_eth0.ip_admin_eth0 = ['val', 'val1', 'val1']
+    assert len(w) == 1
+    assert w[0].message.opt == ip_admin_eth0
+    assert str(w[0].message) == 'invalid value val for option ip_admin_eth0: error'
+    #
+    with warnings.catch_warnings(record=True) as w:
+        cfg.ip_admin_eth0.ip_admin_eth0 = ['val1', 'val', 'val1']
+    assert len(w) == 1
+    assert w[0].message.opt == ip_admin_eth0
+    assert str(w[0].message) == 'invalid value val for option ip_admin_eth0: error'
+    #
+    warnings.resetwarnings()
+    with warnings.catch_warnings(record=True) as w:
+        cfg.ip_admin_eth0.ip_admin_eth0 = ['val1', 'val1', 'val']
+    assert len(w) == 1
+    assert w[0].message.opt == ip_admin_eth0
+    assert str(w[0].message) == 'invalid value val for option ip_admin_eth0: error'
diff --git a/test/test_state.py b/test/test_state.py
index 8587b4a..ef46ce2 100644
--- a/test/test_state.py
+++ b/test/test_state.py
@@ -40,7 +40,7 @@ def _diff_opt(opt1, opt2):
     if diff2 != set():
         raise Exception('more attribute in opt2 {0}'.format(list(diff2)))
     for attr in attr1:
-        if attr in ['_cache_paths']:
+        if attr in ['_cache_paths', '_cache_consistencies']:
             continue
         err1 = False
         err2 = False
@@ -72,7 +72,8 @@ def _diff_opt(opt1, opt2):
             if isinstance(val1, list):
                 for index, consistency in enumerate(val1):
                     assert consistency[0] == val2[index][0]
-                    assert consistency[1]._name == val2[index][1]._name
+                    for idx, opt in enumerate(consistency[1]):
+                        assert opt._name == val2[index][1][idx]._name
         elif attr == '_callback':
             assert val1[0] == val2[0]
             if val1[1] is not None:
diff --git a/tiramisu/autolib.py b/tiramisu/autolib.py
index 20d693c..eb5c6ef 100644
--- a/tiramisu/autolib.py
+++ b/tiramisu/autolib.py
@@ -40,6 +40,13 @@ def carry_out_calculation(name, config, callback, callback_params,
     :param max_len: max length for a multi
     :type max_len: int
 
+    The callback_params is a dict. Key is used to build args (if key is '')
+    and kwargs (otherwise). Values are tuple of:
+    - values
+    - tuple with option and boolean's force_permissive (True when don't raise
+    if PropertiesOptionError)
+    Values could have multiple values only when key is ''.
+
     * if no callback_params:
       => calculate()
 
@@ -91,7 +98,6 @@ def carry_out_calculation(name, config, callback, callback_params,
       - a multi option with an other multi option but with same length
           opt1 == [1, 2, 3]
           opt2 == [11, 12, 13]
-          callback_params={'': ((opt1, False), (opt2, False))}
           => calculate(1, 11)
           => calculate(2, 12)
           => calculate(3, 13)
@@ -99,9 +105,13 @@ def carry_out_calculation(name, config, callback, callback_params,
       - a multi option with an other multi option but with different length
           opt1 == [1, 2, 3]
           opt2 == [11, 12]
-          callback_params={'': ((opt1, False), (opt2, False))}
           => ConfigError()
 
+      - a multi option without value with a simple option
+          opt1 == []
+          opt2 == 11
+          => []
+
     * if callback_params={'value': ((opt1, False), (opt2, False))}
       => ConfigError()
 
@@ -113,39 +123,47 @@ def carry_out_calculation(name, config, callback, callback_params,
     If calculate return list, this list is extend to return value.
     """
     tcparams = {}
+    # if callback_params has a callback, launch several time calculate()
     one_is_multi = False
-    len_multi = 0
+    # multi's option should have same value for all option
+    len_multi = None
 
     for key, callbacks in callback_params.items():
         for callbk in callbacks:
             if isinstance(callbk, tuple):
+                # callbk is something link (opt, True|False)
                 option, force_permissive = callbk
+                path = config.cfgimpl_get_description().impl_get_path_by_opt(
+                    option)
                 # get value
                 try:
-                    path = config.cfgimpl_get_description().impl_get_path_by_opt(option)
                     value = config._getattr(path, force_permissive=True)
                 except PropertiesOptionError as err:
                     if force_permissive:
                         continue
                     raise ConfigError(_('unable to carry out a calculation, '
                                         'option {0} has properties: {1} for: '
-                                        '{2}').format(option._name, err.proptype,
+                                        '{2}').format(option._name,
+                                                      err.proptype,
                                                       name))
                 is_multi = option.impl_is_multi()
                 if is_multi:
-                    if value is not None:
-                        len_value = len(value)
-                        if len_multi != 0 and len_multi != len_value:
-                            raise ConfigError(_('unable to carry out a '
-                                              'calculation, option value with'
-                                              ' multi types must have same '
-                                              'length for: {0}').format(name))
-                        len_multi = len_value
+                    len_value = len(value)
+                    if len_multi is not None and len_multi != len_value:
+                        raise ConfigError(_('unable to carry out a '
+                                            'calculation, option value with'
+                                            ' multi types must have same '
+                                            'length for: {0}').format(name))
+                    len_multi = len_value
                     one_is_multi = True
                 tcparams.setdefault(key, []).append((value, is_multi))
             else:
+                # callbk is a value and not a multi
                 tcparams.setdefault(key, []).append((callbk, False))
 
+    # if one value is a multi, launch several time calculate
+    # if index is set, return a value
+    # if no index, return a list
     if one_is_multi:
         ret = []
         if index:
@@ -160,19 +178,20 @@ def carry_out_calculation(name, config, callback, callback_params,
             else:
                 range_ = range(len_multi)
         for incr in range_:
-            tcp = {}
-            params = []
+            args = []
+            kwargs = {}
             for key, couples in tcparams.items():
                 for couple in couples:
                     value, ismulti = couple
-                    if ismulti and value is not None:
-                        if key == '':
-                            params.append(value[incr])
-                        else:
-                            tcp[key] = value[incr]
+                    if ismulti:
+                        val = value[incr]
                     else:
-                        params.append(value)
-            calc = calculate(name, callback, params, tcp)
+                        val = value
+                    if key == '':
+                        args.append(val)
+                    else:
+                        kwargs[key] = val
+            calc = calculate(callback, args, kwargs)
             if index:
                 ret = calc
             else:
@@ -182,24 +201,26 @@ def carry_out_calculation(name, config, callback, callback_params,
                     ret.append(calc)
         return ret
     else:
-        tcp = {}
-        params = []
+        # no value is multi
+        # return a single value
+        args = []
+        kwargs = {}
         for key, couples in tcparams.items():
             for couple in couples:
+                # couple[1] (ismulti) is always False
                 if key == '':
-                    value = couple[0]
-                    params.append(value)
+                    args.append(couple[0])
                 else:
-                    tcp[key] = couple[0]
-        return calculate(name, callback, params, tcp)
+                    kwargs[key] = couple[0]
+        return calculate(callback, args, kwargs)
 
 
-def calculate(name, callback, params, tcparams):
+def calculate(callback, args, kwargs):
     """wrapper that launches the 'callback'
 
-    :param callback: callback name
-    :param params: in the callback's arity, the unnamed parameters
-    :param tcparams: in the callback's arity, the named parameters
+    :param callback: callback function
+    :param args: in the callback's arity, the unnamed parameters
+    :param kwargs: in the callback's arity, the named parameters
 
     """
-    return callback(*params, **tcparams)
+    return callback(*args, **kwargs)
diff --git a/tiramisu/config.py b/tiramisu/config.py
index 02c6f74..1c05e22 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -1,5 +1,4 @@
 # -*- coding: utf-8 -*-
-"options handler global entry point"
 # Copyright (C) 2012-2013 Team tiramisu (see AUTHORS for all contributors)
 #
 # This program is free software: you can redistribute it and/or modify it
@@ -19,6 +18,7 @@
 # the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
 # the whole pypy projet is under MIT licence
 # ____________________________________________________________
+"options handler global entry point"
 import weakref
 from tiramisu.error import PropertiesOptionError, ConfigError
 from tiramisu.option import OptionDescription, Option, SymLinkOption
@@ -30,7 +30,11 @@ from tiramisu.i18n import _
 
 
 class SubConfig(object):
-    "sub configuration management entry"
+    """Sub configuration management entry.
+    Tree if OptionDescription's responsability. SubConfig are generated
+    on-demand. A Config is also a SubConfig.
+    Root Config is call context below
+    """
     __slots__ = ('_impl_context', '_impl_descr', '_impl_path')
 
     def __init__(self, descr, context, subpath=None):
@@ -55,6 +59,7 @@ class SubConfig(object):
 
     def cfgimpl_reset_cache(self, only_expired=False, only=('values',
                                                             'settings')):
+        "remove cache (in context)"
         self._cfgimpl_get_context().cfgimpl_reset_cache(only_expired, only)
 
     def cfgimpl_get_home_by_path(self, path, force_permissive=False,
@@ -179,7 +184,9 @@ class SubConfig(object):
             homeconfig, name = self.cfgimpl_get_home_by_path(name)
             return homeconfig.__setattr__(name, value)
         child = getattr(self.cfgimpl_get_description(), name)
-        if not isinstance(child, SymLinkOption):
+        if isinstance(child, OptionDescription):
+            raise TypeError(_("can't assign to an OptionDescription"))
+        elif not isinstance(child, SymLinkOption):
             if self._impl_path is None:
                 path = name
             else:
diff --git a/tiramisu/error.py b/tiramisu/error.py
index e4e5991..6a7c8be 100644
--- a/tiramisu/error.py
+++ b/tiramisu/error.py
@@ -56,3 +56,35 @@ class SlaveError(Exception):
 class ConstError(TypeError):
     "no uniq value in _NameSpace"
     pass
+
+
+#Warning
+class ValueWarning(UserWarning):
+    """Option could warn user and not raise ValueError.
+
+    Example:
+
+    >>> import warnings
+    >>> from tiramisu.error import ValueWarning
+    >>> from tiramisu.option import StrOption, OptionDescription
+    >>> from tiramisu.config import Config
+    >>> warnings.simplefilter("always", ValueWarning)
+    >>> def a(val):
+    ...  raise ValueError('pouet')
+    ...
+    >>> s=StrOption('s', '', validator=a, warnings_only=True)
+    >>> o=OptionDescription('o', '', [s])
+    >>> c=Config(o)
+    >>> c.s = 'val'
+    StrOption:0: ValueWarning: invalid value val for option s: pouet
+    >>> with warnings.catch_warnings(record=True) as w:
+    ...     c.s = 'val'
+    ...
+    >>> w[0].message.opt == s
+    True
+    >>> print str(w[0].message)
+    invalid value val for option s: pouet
+    """
+    def __init__(self, msg, opt):
+        self.opt = opt
+        super(ValueWarning, self).__init__(msg)
diff --git a/tiramisu/option.py b/tiramisu/option.py
index 64d3f7e..ca143a0 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -24,8 +24,9 @@ import sys
 from copy import copy, deepcopy
 from types import FunctionType
 from IPy import IP
+import warnings
 
-from tiramisu.error import ConflictError, ConfigError
+from tiramisu.error import ConfigError, ConflictError, ValueWarning
 from tiramisu.setting import groups, multitypes
 from tiramisu.i18n import _
 from tiramisu.autolib import carry_out_calculation
@@ -59,9 +60,8 @@ class BaseOption(object):
     __setattr__ method
     """
     __slots__ = ('_name', '_requires', '_properties', '_readonly',
-                 '_consistencies', '_calc_properties', '_impl_informations',
-                 '_state_consistencies', '_state_readonly', '_state_requires',
-                 '_stated')
+                 '_calc_properties', '_impl_informations',
+                 '_state_readonly', '_state_requires', '_stated')
 
     def __init__(self, name, doc, requires, properties):
         if not valid_name(name):
@@ -71,7 +71,6 @@ class BaseOption(object):
         self.impl_set_information('doc', doc)
         self._calc_properties, self._requires = validate_requires_arg(
             requires, self._name)
-        self._consistencies = None
         if properties is None:
             properties = tuple()
         if not isinstance(properties, tuple):
@@ -96,8 +95,7 @@ class BaseOption(object):
         "frozen" (which has noting to do with the high level "freeze"
         propertie or "read_only" property)
         """
-        if not name.startswith('_state') and name not in ('_cache_paths',
-                                                          '_consistencies'):
+        if not name.startswith('_state') and not name.startswith('_cache'):
             is_readonly = False
             # never change _name
             if name == '_name':
@@ -107,15 +105,12 @@ class BaseOption(object):
                     is_readonly = True
                 except:
                     pass
-            try:
-                if self._readonly is True:
-                    if value is True:
-                        # already readonly and try to re set readonly
-                        # don't raise, just exit
-                        return
-                    is_readonly = True
-            except AttributeError:
-                pass
+            elif name != '_readonly':
+                try:
+                    if self._readonly is True:
+                        is_readonly = True
+                except AttributeError:
+                    self._readonly = False
             if is_readonly:
                 raise AttributeError(_("'{0}' ({1}) object attribute '{2}' is"
                                        " read-only").format(
@@ -147,58 +142,6 @@ class BaseOption(object):
             raise ValueError(_("information's item not found: {0}").format(
                 key))
 
-    # serialize/unserialize
-    def _impl_convert_consistencies(self, descr, load=False):
-        """during serialization process, many things have to be done.
-        one of them is the localisation of the options.
-        The paths are set once for all.
-
-        :type descr: :class:`tiramisu.option.OptionDescription`
-        :param load: `True` if we are at the init of the option description
-        :type load: bool
-        """
-        if not load and self._consistencies is None:
-            self._state_consistencies = None
-        elif load and self._state_consistencies is None:
-            self._consistencies = None
-            del(self._state_consistencies)
-        else:
-            if load:
-                consistencies = self._state_consistencies
-            else:
-                consistencies = self._consistencies
-            if isinstance(consistencies, list):
-                new_value = []
-                for consistency in consistencies:
-                    if load:
-                        new_value.append((consistency[0],
-                                          descr.impl_get_opt_by_path(
-                                              consistency[1])))
-                    else:
-                        new_value.append((consistency[0],
-                                          descr.impl_get_path_by_opt(
-                                              consistency[1])))
-
-            else:
-                new_value = {}
-                for key, _consistencies in consistencies.items():
-                    new_value[key] = []
-                    for key_cons, _cons in _consistencies:
-                        _list_cons = []
-                        for _con in _cons:
-                            if load:
-                                _list_cons.append(
-                                    descr.impl_get_opt_by_path(_con))
-                            else:
-                                _list_cons.append(
-                                    descr.impl_get_path_by_opt(_con))
-                        new_value[key].append((key_cons, tuple(_list_cons)))
-            if load:
-                del(self._state_consistencies)
-                self._consistencies = new_value
-            else:
-                self._state_consistencies = new_value
-
     def _impl_convert_requires(self, descr, load=False):
         """export of the requires during the serialization process
 
@@ -244,10 +187,7 @@ class BaseOption(object):
         for func in dir(self):
             if func.startswith('_impl_convert_'):
                 getattr(self, func)(descr)
-        try:
-            self._state_readonly = self._readonly
-        except AttributeError:
-            pass
+        self._state_readonly = self._readonly
 
     def __getstate__(self, stated=True):
         """special method to enable the serialization with pickle
@@ -267,7 +207,8 @@ class BaseOption(object):
         for subclass in self.__class__.__mro__:
             if subclass is not object:
                 slots.update(subclass.__slots__)
-        slots -= frozenset(['_cache_paths', '__weakref__'])
+        slots -= frozenset(['_cache_paths', '_cache_consistencies',
+                            '__weakref__'])
         states = {}
         for slot in slots:
             # remove variable if save variable converted
@@ -326,13 +267,14 @@ class Option(BaseOption):
     """
     __slots__ = ('_multi', '_validator', '_default_multi', '_default',
                  '_state_callback', '_callback', '_multitype',
-                 '_master_slaves', '__weakref__')
+                 '_consistencies', '_warnings_only', '_master_slaves',
+                 '_state_consistencies', '__weakref__')
     _empty = ''
 
     def __init__(self, name, doc, default=None, default_multi=None,
                  requires=None, multi=False, callback=None,
                  callback_params=None, validator=None, validator_params=None,
-                 properties=None):
+                 properties=None, warnings_only=False):
         """
         :param name: the option's name
         :param doc: the option's description
@@ -350,6 +292,8 @@ class Option(BaseOption):
                           validation of the value
         :param validator_params: the validator's parameters
         :param properties: tuple of default properties
+        :param warnings_only: _validator and _consistencies don't raise if True
+                             Values()._warning contain message
 
         """
         super(Option, self).__init__(name, doc, requires, properties)
@@ -387,58 +331,70 @@ class Option(BaseOption):
                 default = []
             self._multitype = multitypes.default
             self._default_multi = default_multi
+        self._warnings_only = warnings_only
         self.impl_validate(default)
         self._default = default
+        self._consistencies = None
 
-    def _launch_consistency(self, func, opt, vals, context, index, opt_):
+    def _launch_consistency(self, func, option, value, context, index,
+                            all_cons_opts):
+        """Launch consistency now
+
+        :param func: function name, this name should start with _cons_
+        :type func: `str`
+        :param option: option that value is changing
+        :type option: `tiramisu.option.Option`
+        :param value: new value of this option
+        :param context: Config's context, if None, check default value instead
+        :type context: `tiramisu.config.Config`
+        :param index: only for multi option, consistency should be launch for
+                      specified index
+        :type index: `int`
+        :param all_cons_opts: all options concerne by this consistency
+        :type all_cons_opts: `list` of `tiramisu.option.Option`
+        """
         if context is not None:
             descr = context.cfgimpl_get_description()
-        if opt is self:
-            #values are for self, search opt_ values
-            values = vals
-            if context is not None:
-                path = descr.impl_get_path_by_opt(opt_)
-                values_ = context._getattr(path, validate=False)
-            else:
-                values_ = opt_.impl_getdefault()
-            if index is not None:
-                #value is not already set, could be higher
-                try:
-                    values_ = values_[index]
-                except IndexError:
-                    values_ = None
-        else:
-            #values are for opt_, search self values
-            values_ = vals
-            if context is not None:
-                path = descr.impl_get_path_by_opt(self)
-                values = context._getattr(path, validate=False)
-            else:
-                values = self.impl_getdefault()
-            if index is not None:
-                #value is not already set, could be higher
-                try:
-                    values = values[index]
-                except IndexError:
-                    values = None
-        if index is None and self.impl_is_multi():
-            for index in range(0, len(values)):
-                try:
-                    value = values[index]
-                    value_ = values_[index]
-                except IndexError:
-                    value = None
-                    value_ = None
-                if None not in (value, value_):
-                    getattr(self, func)(opt_._name, value, value_)
-        else:
-            if None not in (values, values_):
-                getattr(self, func)(opt_._name, values, values_)
+        #option is also in all_cons_opts
+        if option not in all_cons_opts:
+            raise ConfigError(_('option not in all_cons_opts'))
 
-    def impl_validate(self, value, context=None, validate=True):
+        all_cons_vals = []
+        for opt in all_cons_opts:
+            #get value
+            if option == opt:
+                opt_value = value
+            else:
+                #if context, calculate value, otherwise get default value
+                if context is not None:
+                    opt_value = context._getattr(
+                        descr.impl_get_path_by_opt(opt), validate=False)
+                else:
+                    opt_value = opt.impl_getdefault()
+
+            #append value
+            if not self.impl_is_multi() or option == opt:
+                all_cons_vals.append(opt_value)
+            else:
+                #value is not already set, could be higher index
+                try:
+                    all_cons_vals.append(opt_value[index])
+                except IndexError:
+                    #so return if no value
+                    return
+        getattr(self, func)(all_cons_opts, all_cons_vals)
+
+    def impl_validate(self, value, context=None, validate=True,
+                      force_index=None):
         """
         :param value: the option's value
+        :param context: Config's context
+        :type context: :class:`tiramisu.config.Config`
         :param validate: if true enables ``self._validator`` validation
+        :type validate: boolean
+        :param force_no_multi: if multi, value has to be a list
+                               not if force_no_multi is True
+        :type force_no_multi: boolean
         """
         if not validate:
             return
@@ -455,45 +411,44 @@ class Option(BaseOption):
                         validator_params[''] = (val,)
                 else:
                     validator_params = {'': (val,)}
-                ret = carry_out_calculation(self._name, config=context,
-                                            callback=self._validator[0],
-                                            callback_params=validator_params)
-                if ret not in [False, True]:
-                    raise ConfigError(_('validator should return a boolean, '
-                                        'not {0}').format(ret))
-                return ret
-            else:
-                return True
+                # Raise ValueError if not valid
+                carry_out_calculation(self._name, config=context,
+                                      callback=self._validator[0],
+                                      callback_params=validator_params)
 
         def do_validation(_value, _index=None):
             if _value is None:
-                return True
-            if not val_validator(_value):
-                raise ValueError(_("invalid value {0} "
-                                   "for option {1} for object {2}"
-                                   ).format(_value,
-                                            self._name,
-                                            self.__class__.__name__))
+                return
+            # option validation
+            self._validate(_value)
             try:
-                self._validate(_value)
+                # valid with self._validator
+                val_validator(_value)
+                # if not context launch consistency validation
+                if context is not None:
+                    descr._valid_consistency(self, _value, context, _index)
+                self._second_level_validation(_value)
             except ValueError as err:
-                raise ValueError(_("invalid value {0} for option {1}: {2}"
-                                   "").format(_value, self._name, err))
-            if context is not None:
-                descr._valid_consistency(self, _value, context, _index)
+                msg = _("invalid value {0} for option {1}: {2}").format(
+                    _value, self._name, err)
+                if self._warnings_only:
+                    warnings.warn_explicit(ValueWarning(msg, self),
+                                           ValueWarning,
+                                           self.__class__.__name__, 0)
+                else:
+                    raise ValueError(msg)
 
         # generic calculation
         if context is not None:
             descr = context.cfgimpl_get_description()
-        if not self._multi:
-            do_validation(value)
+
+        if not self._multi or force_index is not None:
+            do_validation(value, force_index)
         else:
             if not isinstance(value, list):
-                raise ValueError(_("invalid value {0} for option {1} "
-                                   "which must be a list").format(value,
+                raise ValueError(_("which must be a list").format(value,
                                                                   self._name))
-            for index in range(0, len(value)):
-                val = value[index]
+            for index, val in enumerate(value):
                 do_validation(val, index)
 
     def impl_getdefault(self, default_multi=False):
@@ -538,29 +493,45 @@ class Option(BaseOption):
     def impl_is_multi(self):
         return self._multi
 
-    def impl_add_consistency(self, func, opt):
+    def impl_add_consistency(self, func, *other_opts):
+        """Add consistency means that value will be validate with other_opts
+        option's values.
+
+        :param func: function's name
+        :type func: `str`
+        :param other_opts: options used to validate value
+        :type other_opts: `list` of `tiramisu.option.Option`
+        """
         if self._consistencies is None:
             self._consistencies = []
-        if not isinstance(opt, Option):
-            raise ValueError('consistency must be set with an option')
-        if self is opt:
-            raise ValueError('cannot add consistency with itself')
-        if self.impl_is_multi() != opt.impl_is_multi():
-            raise ValueError('options in consistency'
-                             ' should be multi in two sides')
+        for opt in other_opts:
+            if not isinstance(opt, Option):
+                raise ConfigError(_('consistency should be set with an option'))
+            if self is opt:
+                raise ConfigError(_('cannot add consistency with itself'))
+            if self.impl_is_multi() != opt.impl_is_multi():
+                raise ConfigError(_('every options in consistency should be '
+                                    'multi or none'))
         func = '_cons_{0}'.format(func)
-        self._launch_consistency(func,
-                                 self,
-                                 self.impl_getdefault(),
-                                 None, None, opt)
-        self._consistencies.append((func, opt))
+        all_cons_opts = tuple([self] + list(other_opts))
+        value = self.impl_getdefault()
+        if value is not None:
+            if self.impl_is_multi():
+                for idx, val in enumerate(value):
+                    self._launch_consistency(func, self, val, None,
+                                             idx, all_cons_opts)
+            else:
+                self._launch_consistency(func, self, value, None,
+                                         None, all_cons_opts)
+        self._consistencies.append((func, all_cons_opts))
         self.impl_validate(self.impl_getdefault())
 
-    def _cons_not_equal(self, optname, value, value_):
-        if value == value_:
-            raise ValueError(_("invalid value {0} for option {1} "
-                               "must be different as {2} option"
-                               "").format(value, self._name, optname))
+    def _cons_not_equal(self, opts, vals):
+        for idx_inf, val_inf in enumerate(vals):
+            for idx_sup, val_sup in enumerate(vals[idx_inf + 1:]):
+                if val_inf == val_sup is not None:
+                    raise ValueError(_("same value for {0} and {1}").format(
+                        opts[idx_inf]._name, opts[idx_inf + idx_sup + 1]._name))
 
     def _impl_convert_callbacks(self, descr, load=False):
         if not load and self._callback is None:
@@ -596,6 +567,60 @@ class Option(BaseOption):
             else:
                 self._state_callback = (callback, cllbck_prms)
 
+    # serialize/unserialize
+    def _impl_convert_consistencies(self, descr, load=False):
+        """during serialization process, many things have to be done.
+        one of them is the localisation of the options.
+        The paths are set once for all.
+
+        :type descr: :class:`tiramisu.option.OptionDescription`
+        :param load: `True` if we are at the init of the option description
+        :type load: bool
+        """
+        if not load and self._consistencies is None:
+            self._state_consistencies = None
+        elif load and self._state_consistencies is None:
+            self._consistencies = None
+            del(self._state_consistencies)
+        else:
+            if load:
+                consistencies = self._state_consistencies
+            else:
+                consistencies = self._consistencies
+            if isinstance(consistencies, list):
+                new_value = []
+                for consistency in consistencies:
+                    values = []
+                    for obj in consistency[1]:
+                        if load:
+                            values.append(descr.impl_get_opt_by_path(obj))
+                        else:
+                            values.append(descr.impl_get_path_by_opt(obj))
+                    new_value.append((consistency[0], tuple(values)))
+
+            else:
+                new_value = {}
+                for key, _consistencies in consistencies.items():
+                    new_value[key] = []
+                    for key_cons, _cons in _consistencies:
+                        _list_cons = []
+                        for _con in _cons:
+                            if load:
+                                _list_cons.append(
+                                    descr.impl_get_opt_by_path(_con))
+                            else:
+                                _list_cons.append(
+                                    descr.impl_get_path_by_opt(_con))
+                        new_value[key].append((key_cons, tuple(_list_cons)))
+            if load:
+                del(self._state_consistencies)
+                self._consistencies = new_value
+            else:
+                self._state_consistencies = new_value
+
+    def _second_level_validation(self, value):
+        pass
+
 
 class ChoiceOption(Option):
     """represents a choice out of several objects.
@@ -609,7 +634,7 @@ class ChoiceOption(Option):
     def __init__(self, name, doc, values, default=None, default_multi=None,
                  requires=None, multi=False, callback=None,
                  callback_params=None, open_values=False, validator=None,
-                 validator_params=None, properties=()):
+                 validator_params=None, properties=None, warnings_only=False):
         """
         :param values: is a list of values the option can possibly take
         """
@@ -628,7 +653,8 @@ class ChoiceOption(Option):
                                            multi=multi,
                                            validator=validator,
                                            validator_params=validator_params,
-                                           properties=properties)
+                                           properties=properties,
+                                           warnings_only=warnings_only)
 
     def impl_get_values(self):
         return self._values
@@ -705,7 +731,7 @@ class SymLinkOption(BaseOption):
     __slots__ = ('_name', '_opt', '_state_opt')
     _opt_type = 'symlink'
     #not return _opt consistencies
-    _consistencies = {}
+    _consistencies = None
 
     def __init__(self, name, opt):
         self._name = name
@@ -731,23 +757,18 @@ class SymLinkOption(BaseOption):
         del(self._state_opt)
         super(SymLinkOption, self)._impl_setstate(descr)
 
-    def _impl_convert_consistencies(self, descr, load=False):
-        if load:
-            del(self._state_consistencies)
-        else:
-            self._state_consistencies = None
-
 
 class IPOption(Option):
     "represents the choice of an ip"
-    __slots__ = ('_only_private', '_allow_reserved')
+    __slots__ = ('_private_only', '_allow_reserved')
     _opt_type = 'ip'
 
     def __init__(self, name, doc, default=None, default_multi=None,
                  requires=None, multi=False, callback=None,
                  callback_params=None, validator=None, validator_params=None,
-                 properties=None, only_private=False, allow_reserved=False):
-        self._only_private = only_private
+                 properties=None, private_only=False, allow_reserved=False,
+                 warnings_only=False):
+        self._private_only = private_only
         self._allow_reserved = allow_reserved
         super(IPOption, self).__init__(name, doc, default=default,
                                        default_multi=default_multi,
@@ -757,13 +778,20 @@ class IPOption(Option):
                                        multi=multi,
                                        validator=validator,
                                        validator_params=validator_params,
-                                       properties=properties)
+                                       properties=properties,
+                                       warnings_only=warnings_only)
 
     def _validate(self, value):
+        try:
+            IP('{0}/32'.format(value))
+        except ValueError:
+            raise ValueError(_('invalid IP {0}').format(self._name))
+
+    def _second_level_validation(self, value):
         ip = IP('{0}/32'.format(value))
         if not self._allow_reserved and ip.iptype() == 'RESERVED':
             raise ValueError(_("IP mustn't not be in reserved class"))
-        if self._only_private and not ip.iptype() == 'PRIVATE':
+        if self._private_only and not ip.iptype() == 'PRIVATE':
             raise ValueError(_("IP must be in private class"))
 
 
@@ -785,7 +813,7 @@ class PortOption(Option):
                  callback_params=None, validator=None, validator_params=None,
                  properties=None, allow_range=False, allow_zero=False,
                  allow_wellknown=True, allow_registred=True,
-                 allow_private=False):
+                 allow_private=False, warnings_only=False):
         self._allow_range = allow_range
         self._min_value = None
         self._max_value = None
@@ -817,7 +845,8 @@ class PortOption(Option):
                                          multi=multi,
                                          validator=validator,
                                          validator_params=validator_params,
-                                         properties=properties)
+                                         properties=properties,
+                                         warnings_only=warnings_only)
 
     def _validate(self, value):
         if self._allow_range and ":" in str(value):
@@ -842,6 +871,12 @@ class NetworkOption(Option):
     _opt_type = 'network'
 
     def _validate(self, value):
+        try:
+            IP(value)
+        except ValueError:
+            raise ValueError(_('invalid network address {0}').format(self._name))
+
+    def _second_level_validation(self, value):
         ip = IP(value)
         if ip.iptype() == 'RESERVED':
             raise ValueError(_("network shall not be in reserved class"))
@@ -853,18 +888,26 @@ class NetmaskOption(Option):
     _opt_type = 'netmask'
 
     def _validate(self, value):
-        IP('0.0.0.0/{0}'.format(value))
+        try:
+            IP('0.0.0.0/{0}'.format(value))
+        except ValueError:
+            raise ValueError(_('invalid netmask address {0}').format(self._name))
 
-    def _cons_network_netmask(self, optname, value, value_):
+    def _cons_network_netmask(self, opts, vals):
         #opts must be (netmask, network) options
-        self.__cons_netmask(optname, value, value_, False)
+        if None in vals:
+            return
+        self.__cons_netmask(opts, vals[0], vals[1], False)
 
-    def _cons_ip_netmask(self, optname, value, value_):
+    def _cons_ip_netmask(self, opts, vals):
         #opts must be (netmask, ip) options
-        self.__cons_netmask(optname, value, value_, True)
+        if None in vals:
+            return
+        self.__cons_netmask(opts, vals[0], vals[1], True)
 
-    #def __cons_netmask(self, opt, value, context, index, opts, make_net):
-    def __cons_netmask(self, optname, val_netmask, val_ipnetwork, make_net):
+    def __cons_netmask(self, opts, val_netmask, val_ipnetwork, make_net):
+        if len(opts) != 2:
+            raise ConfigError(_('invalid len for opts'))
         msg = None
         try:
             ip = IP('{0}/{1}'.format(val_ipnetwork, val_netmask),
@@ -890,23 +933,48 @@ class NetmaskOption(Option):
             else:
                 msg = _("invalid network {0} ({1}) with netmask {2} ({3})")
         if msg is not None:
-            raise ValueError(msg.format(val_ipnetwork, optname,
+            raise ValueError(msg.format(val_ipnetwork, opts[1]._name,
                                         val_netmask, self._name))
 
 
+class BroadcastOption(Option):
+    __slots__ = tuple()
+    _opt_type = 'broadcast'
+
+    def _validate(self, value):
+        try:
+            IP('{0}/32'.format(value))
+        except ValueError:
+            raise ValueError(_('invalid broadcast address {0}').format(self._name))
+
+    def _cons_broadcast(self, opts, vals):
+        if len(vals) != 3:
+            raise ConfigError(_('invalid len for vals'))
+        if None in vals:
+            return
+        broadcast, network, netmask = vals
+        if IP('{0}/{1}'.format(network, netmask)).broadcast() != IP(broadcast):
+            raise ValueError(_('invalid broadcast {0} ({1}) with network {2} '
+                               '({3}) and netmask {4} ({5})').format(
+                                   broadcast, opts[0]._name, network,
+                                   opts[1]._name, netmask, opts[2]._name))
+
+
 class DomainnameOption(Option):
-    "represents the choice of a domain name"
+    """represents the choice of a domain name
+    netbios: for MS domain
+    hostname: to identify the device
+    domainname:
+    fqdn: with tld, not supported yet
+    """
     __slots__ = ('_type', '_allow_ip')
     _opt_type = 'domainname'
 
     def __init__(self, name, doc, default=None, default_multi=None,
                  requires=None, multi=False, callback=None,
                  callback_params=None, validator=None, validator_params=None,
-                 properties=None, allow_ip=False, type_='domainname'):
-        #netbios: for MS domain
-        #hostname: to identify the device
-        #domainname:
-        #fqdn: with tld, not supported yet
+                 properties=None, allow_ip=False, type_='domainname',
+                 warnings_only=False):
         if type_ not in ['netbios', 'hostname', 'domainname']:
             raise ValueError(_('unknown type_ {0} for hostname').format(type_))
         self._type = type_
@@ -921,7 +989,8 @@ class DomainnameOption(Option):
                                                multi=multi,
                                                validator=validator,
                                                validator_params=validator_params,
-                                               properties=properties)
+                                               properties=properties,
+                                               warnings_only=warnings_only)
 
     def _validate(self, value):
         if self._allow_ip is True:
@@ -959,9 +1028,9 @@ class OptionDescription(BaseOption):
     """
     __slots__ = ('_name', '_requires', '_cache_paths', '_group_type',
                  '_state_group_type', '_properties', '_children',
-                 '_consistencies', '_calc_properties', '__weakref__',
+                 '_cache_consistencies', '_calc_properties', '__weakref__',
                  '_readonly', '_impl_informations', '_state_requires',
-                 '_state_consistencies', '_stated', '_state_readonly')
+                 '_stated', '_state_readonly')
     _opt_type = 'optiondescription'
 
     def __init__(self, name, doc, children, requires=None, properties=None):
@@ -982,6 +1051,7 @@ class OptionDescription(BaseOption):
             old = child
         self._children = (tuple(child_names), tuple(children))
         self._cache_paths = None
+        self._cache_consistencies = None
         # the group_type is useful for filtering OptionDescriptions in a config
         self._group_type = groups.default
 
@@ -1055,12 +1125,11 @@ class OptionDescription(BaseOption):
                 if not force_no_consistencies and \
                         option._consistencies is not None:
                     for consistency in option._consistencies:
-                        func, opt = consistency
-                        opts = (option, opt)
-                        _consistencies.setdefault(opt,
-                                                  []).append((func, opts))
-                        _consistencies.setdefault(option,
-                                                  []).append((func, opts))
+                        func, all_cons_opts = consistency
+                        for opt in all_cons_opts:
+                            _consistencies.setdefault(opt,
+                                                      []).append((func,
+                                                                  all_cons_opts))
             else:
                 _currpath.append(attr)
                 option.impl_build_cache(cache_path,
@@ -1072,7 +1141,12 @@ class OptionDescription(BaseOption):
         if save:
             self._cache_paths = (tuple(cache_option), tuple(cache_path))
             if not force_no_consistencies:
-                self._consistencies = _consistencies
+                if _consistencies != {}:
+                    self._cache_consistencies = {}
+                    for opt, cons in _consistencies.items():
+                        if opt not in cache_option:
+                            raise ConfigError(_('consistency with option {0} which is not in Config').format(opt._name))
+                        self._cache_consistencies[opt] = tuple(cons)
                 self._readonly = True
 
     def impl_get_opt_by_path(self, path):
@@ -1143,17 +1217,18 @@ class OptionDescription(BaseOption):
     def impl_get_group_type(self):
         return self._group_type
 
-    def _valid_consistency(self, opt, value, context=None, index=None):
-        consistencies = self._consistencies.get(opt)
+    def _valid_consistency(self, option, value, context, index):
+        if self._cache_consistencies is None:
+            return True
+        #consistencies is something like [('_cons_not_equal', (opt1, opt2))]
+        consistencies = self._cache_consistencies.get(option)
         if consistencies is not None:
-            for consistency in consistencies:
-                opt_ = consistency[1]
-                ret = opt_[0]._launch_consistency(consistency[0],
-                                                  opt,
-                                                  value,
-                                                  context,
-                                                  index,
-                                                  opt_[1])
+            for func, all_cons_opts in consistencies:
+                #all_cons_opts[0] is the option where func is set
+                ret = all_cons_opts[0]._launch_consistency(func, option,
+                                                           value,
+                                                           context, index,
+                                                           all_cons_opts)
                 if ret is False:
                     return False
         return True
@@ -1193,6 +1268,7 @@ class OptionDescription(BaseOption):
         """
         if descr is None:
             self._cache_paths = None
+            self._cache_consistencies = None
             self.impl_build_cache(force_no_consistencies=True)
             descr = self
         self._group_type = getattr(groups, self._state_group_type)
@@ -1324,6 +1400,6 @@ def validate_callback(callback, callback_params, type_):
                                            ).format(type_, type(option)))
                     if force_permissive not in [True, False]:
                         raise ValueError(_('{0}_params should have a boolean'
-                                           'not a {0} for second argument'
+                                           ' not a {0} for second argument'
                                            ).format(type_, type(
                                                force_permissive)))
diff --git a/tiramisu/value.py b/tiramisu/value.py
index f1833fb..7fd34db 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -104,7 +104,8 @@ class Values(object):
             path = self._get_opt_path(opt)
         if self._p_.hasvalue(path):
             setting = self.context().cfgimpl_get_settings()
-            opt.impl_validate(opt.impl_getdefault(), self.context(),
+            opt.impl_validate(opt.impl_getdefault(),
+                              self.context(),
                               'validator' in setting)
             self.context().cfgimpl_reset_cache()
             if (opt.impl_is_multi() and
@@ -237,7 +238,7 @@ class Values(object):
                                         force_properties=force_properties,
                                         force_permissives=force_permissives)
         if config_error is not None:
-            raise ConfigError(config_error)
+            raise config_error
         return value
 
     def __setitem__(self, opt, value):
@@ -368,6 +369,7 @@ class Values(object):
     def __setstate__(self, states):
         self._p_ = states['_p_']
 
+
 # ____________________________________________________________
 # multi types
 
@@ -451,10 +453,10 @@ class Multi(list):
                             value_slave.append(slave.impl_getdefault_multi(),
                                                force=True)
 
-    def __setitem__(self, key, value):
-        self._validate(value)
+    def __setitem__(self, index, value):
+        self._validate(value, index)
         #assume not checking mandatory property
-        super(Multi, self).__setitem__(key, value)
+        super(Multi, self).__setitem__(index, value)
         self.context().cfgimpl_get_values()._setvalue(self.opt, self.path, self)
 
     def append(self, value, force=False):
@@ -472,15 +474,17 @@ class Multi(list):
                     #Force None il return a list
                     if isinstance(value, list):
                         value = None
-        self._validate(value)
+        index = self.__len__()
+        self._validate(value, index)
         super(Multi, self).append(value)
-        self.context().cfgimpl_get_values()._setvalue(self.opt, self.path, self, validate_properties=not force)
+        self.context().cfgimpl_get_values()._setvalue(self.opt, self.path,
+                                                      self,
+                                                      validate_properties=not force)
         if not force and self.opt.impl_get_multitype() == multitypes.master:
             for slave in self.opt.impl_get_master_slaves():
                 path = values._get_opt_path(slave)
                 if not values._is_default_owner(path):
                     if slave.impl_has_callback():
-                        index = self.__len__() - 1
                         dvalue = values._getcallback_value(slave, index=index)
                     else:
                         dvalue = slave.impl_getdefault_multi()
@@ -532,10 +536,11 @@ class Multi(list):
         super(Multi, self).extend(iterable)
         self.context().cfgimpl_get_values()._setvalue(self.opt, self.path, self)
 
-    def _validate(self, value):
+    def _validate(self, value, force_index):
         if value is not None:
             try:
-                self.opt._validate(value)
+                self.opt.impl_validate(value, context=self.context(),
+                                       force_index=force_index)
             except ValueError as err:
                 raise ValueError(_("invalid value {0} "
                                    "for option {1}: {2}"
diff --git a/translations/fr/tiramisu.po b/translations/fr/tiramisu.po
index 8bceb43..0075059 100644
--- a/translations/fr/tiramisu.po
+++ b/translations/fr/tiramisu.po
@@ -2,7 +2,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2013-08-31 09:52+CEST\n"
+"POT-Creation-Date: 2013-09-26 22:33+CEST\n"
 "PO-Revision-Date: \n"
 "Last-Translator: Emmanuel Garette <egarette@cadoles.com>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -11,436 +11,486 @@ msgstr ""
 "Content-Transfer-Encoding: 8bit\n"
 "X-Generator: Poedit 1.5.4\n"
 
-#: tiramisu/autolib.py:58
-msgid "no config specified but needed"
-msgstr "aucune config spécifié alors que c'est nécessaire"
-
-#: tiramisu/autolib.py:65
+#: tiramisu/autolib.py:145
 msgid ""
 "unable to carry out a calculation, option {0} has properties: {1} for: {2}"
 msgstr ""
 "impossible d'effectuer le calcul, l'option {0} a les propriétés : {1} pour : "
 "{2}"
 
-#: tiramisu/autolib.py:74
+#: tiramisu/autolib.py:154
 msgid ""
 "unable to carry out a calculation, option value with multi types must have "
 "same length for: {0}"
 msgstr ""
-"impossible d'effectuer le calcul, valeur d'un option avec le type multi doit "
-"avoir la même longueur pour : {0}"
+"impossible d'effectuer le calcul, la valeur d'une option avec le type multi "
+"doit avoir la même longueur pour : {0}"
 
-#: tiramisu/config.py:47
+#: tiramisu/config.py:52
 msgid "descr must be an optiondescription, not {0}"
 msgstr "descr doit être une optiondescription pas un {0}"
 
-#: tiramisu/config.py:121
+#: tiramisu/config.py:127
 msgid "unknown group_type: {0}"
 msgstr "group_type inconnu: {0}"
 
-#: tiramisu/config.py:157
+#: tiramisu/config.py:163
 msgid ""
 "no option description found for this config (may be metaconfig without meta)"
 msgstr ""
-"pas d'option description pour cette config (peut être une metaconfig sans "
-"meta)"
+"pas d'option description trouvé pour cette config (peut être une metaconfig "
+"sans meta)"
 
-#: tiramisu/config.py:311
+#: tiramisu/config.py:189
+msgid "can't assign to an OptionDescription"
+msgstr "ne peut pas attribuer une valeur à une OptionDescription"
+
+#: tiramisu/config.py:320
 msgid "unknown type_ type {0}for _find"
 msgstr "type_ type {0} pour _find inconnu"
 
-#: tiramisu/config.py:350
+#: tiramisu/config.py:359
 msgid "no option found in config with these criteria"
 msgstr "aucune option trouvée dans la config avec ces critères"
 
-#: tiramisu/config.py:400
+#: tiramisu/config.py:409
 msgid "make_dict can't filtering with value without option"
 msgstr "make_dict ne peut filtrer sur une valeur mais sans option"
 
-#: tiramisu/config.py:421
+#: tiramisu/config.py:430
 msgid "unexpected path {0}, should start with {1}"
 msgstr "chemin imprévu {0}, devrait commencer par {1}"
 
-#: tiramisu/config.py:481
+#: tiramisu/config.py:490
 msgid "opt in getowner must be an option not {0}"
 msgstr "opt dans getowner doit être une option pas {0}"
 
-#: tiramisu/option.py:71
-msgid "{0} has no attribute impl_set_information"
-msgstr "{0} n'a pas d'attribut impl_set_information"
-
-#: tiramisu/option.py:86
-msgid "information's item not found: {0}"
-msgstr "aucune config spécifié alors que c'est nécessaire"
-
-#: tiramisu/option.py:89
-msgid "{0} has no attribute impl_get_information"
-msgstr "{0} n'a pas d'attribut impl_get_information"
-
-#: tiramisu/option.py:117
-msgid "'{0}' ({1}) object attribute '{2}' is read-only"
-msgstr "l'attribut {2} de l'objet '{0}' ({1}) est en lecture seul"
-
-#: tiramisu/option.py:159
+#: tiramisu/option.py:70
 msgid "invalid name: {0} for option"
 msgstr "nom invalide : {0} pour l'option"
 
-#: tiramisu/option.py:169
-msgid "validator must be a function"
-msgstr "validator doit être une fonction"
+#: tiramisu/option.py:80
+msgid "invalid properties type {0} for {1}, must be a tuple"
+msgstr "type des properties invalide {0} pour {1}, doit être un tuple"
 
-#: tiramisu/option.py:176
+#: tiramisu/option.py:122
+msgid "'{0}' ({1}) object attribute '{2}' is read-only"
+msgstr "l'attribut {2} de l'objet '{0}' ({1}) est en lecture seule"
+
+#: tiramisu/option.py:149 tiramisu/value.py:362
+msgid "information's item not found: {0}"
+msgstr "aucune config spécifié alors que c'est nécessaire"
+
+#: tiramisu/option.py:266
+msgid "cannot serialize Option, only in OptionDescription"
+msgstr "ne peut serialiser une Option, seulement via une OptionDescription"
+
+#: tiramisu/option.py:367
 msgid "a default_multi is set whereas multi is False in option: {0}"
 msgstr ""
-"une default_multi est renseigné alors que multi est False dans l'option : {0}"
+"une default_multi est renseignée alors que multi est False dans l'option : "
+"{0}"
 
-#: tiramisu/option.py:182
+#: tiramisu/option.py:373
 msgid "invalid default_multi value {0} for option {1}: {2}"
 msgstr "la valeur default_multi est invalide {0} pour l'option {1} : {2}"
 
-#: tiramisu/option.py:187
+#: tiramisu/option.py:378
 msgid "default value not allowed if option: {0} is calculated"
-msgstr "la valeur par défaut n'est pas possible si l'option {0} est calculé"
+msgstr "la valeur par défaut n'est pas possible si l'option {0} est calculée"
 
-#: tiramisu/option.py:190
+#: tiramisu/option.py:381
 msgid ""
 "params defined for a callback function but no callback defined yet for "
 "option {0}"
 msgstr ""
-"params définit pour une fonction callback mais par de callback défini encore "
-"pour l'option {0}"
+"params définis pour une fonction callback mais par de callback encore "
+"définis pour l'option {0}"
 
-#: tiramisu/option.py:212 tiramisu/option.py:753
-msgid "invalid properties type {0} for {1}, must be a tuple"
-msgstr "type des properties invalide {0} pour {1}, doit être un tuple"
-
-#: tiramisu/option.py:285
-msgid "invalid value {0} for option {1} for object {2}"
-msgstr "valeur invalide {0} pour l'option {1} pour l'objet {2}"
-
-#: tiramisu/option.py:293 tiramisu/value.py:468
+#: tiramisu/option.py:486 tiramisu/value.py:547
 msgid "invalid value {0} for option {1}: {2}"
 msgstr "valeur invalide {0} pour l'option {1} : {2}"
 
-#: tiramisu/option.py:305
+#: tiramisu/option.py:506
 msgid "invalid value {0} for option {1} which must be a list"
 msgstr "valeur invalide {0} pour l'option {1} qui doit être une liste"
 
-#: tiramisu/option.py:374
+#: tiramisu/option.py:577
 msgid "invalid value {0} for option {1} must be different as {2} option"
 msgstr ""
-"valeur invalide {0} pour l'option {1} doit être différent que l'option {2}"
+"valeur invalide {0} pour l'option {1} doit être différente de l'option {2}"
 
-#: tiramisu/option.py:396
+#: tiramisu/option.py:636
 msgid "values must be a tuple for {0}"
 msgstr "values doit être un tuple pour {0}"
 
-#: tiramisu/option.py:399
+#: tiramisu/option.py:639
 msgid "open_values must be a boolean for {0}"
 msgstr "open_values doit être un booléen pour {0}"
 
-#: tiramisu/option.py:420
+#: tiramisu/option.py:661
 msgid "value {0} is not permitted, only {1} is allowed"
-msgstr "valeur {0} n'est pas permit, seules {1} sont autorisées"
+msgstr "valeur {0} n'est pas permis, seules {1} sont autorisées"
 
-#: tiramisu/option.py:432
+#: tiramisu/option.py:673
 msgid "value must be a boolean"
 msgstr "valeur doit être un booléen"
 
-#: tiramisu/option.py:442
+#: tiramisu/option.py:683
 msgid "value must be an integer"
-msgstr "valeur doit être un numbre"
+msgstr "valeur doit être un nombre entier"
 
-#: tiramisu/option.py:452
+#: tiramisu/option.py:693
 msgid "value must be a float"
 msgstr "valeur doit être un nombre flottant"
 
-#: tiramisu/option.py:462
+#: tiramisu/option.py:703
 msgid "value must be a string, not {0}"
 msgstr "valeur doit être une chaîne, pas {0}"
 
-#: tiramisu/option.py:480
+#: tiramisu/option.py:721
 msgid "value must be an unicode"
 msgstr "valeur doit être une valeur unicode"
 
-#: tiramisu/option.py:490
+#: tiramisu/option.py:733
 msgid "malformed symlinkoption must be an option for symlink {0}"
-msgstr "symlinkoption mal formé doit être une option pour symlink {0}"
+msgstr "symlinkoption mal formé, doit être une option pour symlink {0}"
 
-#: tiramisu/option.py:526
-msgid "IP shall not be in reserved class"
+#: tiramisu/option.py:788
+msgid "invalid IP {0}"
+msgstr "adresse IP invalide {0}"
+
+#: tiramisu/option.py:793
+msgid "IP mustn't not be in reserved class"
 msgstr "IP ne doit pas être d'une classe reservée"
 
-#: tiramisu/option.py:528
+#: tiramisu/option.py:795
 msgid "IP must be in private class"
 msgstr "IP doit être dans la classe privée"
 
-#: tiramisu/option.py:566
+#: tiramisu/option.py:833
 msgid "inconsistency in allowed range"
 msgstr "inconsistence dans la plage autorisée"
 
-#: tiramisu/option.py:571
+#: tiramisu/option.py:838
 msgid "max value is empty"
-msgstr "valeur maximum est vide"
+msgstr "la valeur maximum est vide"
 
-#: tiramisu/option.py:608
+#: tiramisu/option.py:877
+msgid "invalid network address {0}"
+msgstr "adresse réseau invalide {0}"
+
+#: tiramisu/option.py:882
 msgid "network shall not be in reserved class"
-msgstr "réseau ne doit pas être dans la classe reservée"
+msgstr "le réseau ne doit pas être dans la classe reservée"
 
-#: tiramisu/option.py:640
+#: tiramisu/option.py:894
+msgid "invalid netmask address {0}"
+msgstr "masque de sous-réseau invalide {0}"
+
+#: tiramisu/option.py:916
 msgid "invalid network {0} ({1}) with netmask {2} ({3}), this network is an IP"
 msgstr "réseau invalide {0} ({1}) avec masque {2} ({3}), ce réseau est une IP"
 
-#: tiramisu/option.py:645
+#: tiramisu/option.py:921
 msgid "invalid IP {0} ({1}) with netmask {2} ({3}), this IP is a network"
 msgstr "IP invalide {0} ({1}) avec masque {2} ({3}), cette IP est un réseau"
 
-#: tiramisu/option.py:650
+#: tiramisu/option.py:926
 msgid "invalid IP {0} ({1}) with netmask {2} ({3})"
 msgstr "IP invalide {0} ({1}) avec masque {2} ({3})"
 
-#: tiramisu/option.py:652
+#: tiramisu/option.py:928
 msgid "invalid network {0} ({1}) with netmask {2} ({3})"
 msgstr "réseau invalide {0} ({1}) avec masque {2} ({3})"
 
-#: tiramisu/option.py:672
+#: tiramisu/option.py:939
+msgid "invalid broadcast address {0}"
+msgstr "adresse de broadcast invalide {0}"
+
+#: tiramisu/option.py:957
 msgid "unknown type_ {0} for hostname"
 msgstr "type_ inconnu {0} pour le nom d'hôte"
 
-#: tiramisu/option.py:675
+#: tiramisu/option.py:960
 msgid "allow_ip must be a boolean"
 msgstr "allow_ip doit être un booléen"
 
-#: tiramisu/option.py:704
+#: tiramisu/option.py:990
 msgid "invalid value for {0}, must have dot"
 msgstr "valeur invalide pour {0}, doit avoir un point"
 
-#: tiramisu/option.py:707
+#: tiramisu/option.py:993
 msgid "invalid domainname's length for {0} (max {1})"
 msgstr "longueur du nom de domaine invalide pour {0} (maximum {1})"
 
-#: tiramisu/option.py:710
+#: tiramisu/option.py:996
 msgid "invalid domainname's length for {0} (min 2)"
 msgstr "longueur du nom de domaine invalide pour {0} (minimum 2)"
 
-#: tiramisu/option.py:714
+#: tiramisu/option.py:1000
 msgid "invalid domainname"
 msgstr "nom de domaine invalide"
 
-#: tiramisu/option.py:731
-msgid "invalid name: {0} for optiondescription"
-msgstr "nom invalide : {0} pour l'optiondescription"
-
-#: tiramisu/option.py:743
+#: tiramisu/option.py:1027
 msgid "duplicate option name: {0}"
 msgstr "nom de l'option dupliqué : {0}"
 
-#: tiramisu/option.py:769
+#: tiramisu/option.py:1044
 msgid "unknown Option {0} in OptionDescription {1}"
-msgstr "Option {} inconnue pour l'OptionDescription{}"
+msgstr "Option {0} inconnue pour l'OptionDescription {1}"
 
-#: tiramisu/option.py:820
+#: tiramisu/option.py:1095
 msgid "duplicate option: {0}"
 msgstr "option dupliquée : {0}"
 
-#: tiramisu/option.py:850
+#: tiramisu/option.py:1129
 msgid "no option for path {0}"
 msgstr "pas d'option pour le chemin {0}"
 
-#: tiramisu/option.py:856
+#: tiramisu/option.py:1135
 msgid "no option {0} found"
 msgstr "pas d'option {0} trouvée"
 
-#: tiramisu/option.py:866
+#: tiramisu/option.py:1145
 msgid "cannot change group_type if already set (old {0}, new {1})"
 msgstr "ne peut changer group_type si déjà spécifié (ancien {0}, nouveau {1})"
 
-#: tiramisu/option.py:879
+#: tiramisu/option.py:1158
 msgid "master group {0} shall not have a subgroup"
 msgstr "groupe maître {0} ne doit pas avoir de sous-groupe"
 
-#: tiramisu/option.py:882
+#: tiramisu/option.py:1161
 msgid "master group {0} shall not have a symlinkoption"
 msgstr "groupe maître {0} ne doit pas avoir de symlinkoption"
 
-#: tiramisu/option.py:885
+#: tiramisu/option.py:1164
 msgid "not allowed option {0} in group {1}: this option is not a multi"
 msgstr ""
 "option non autorisée {0} dans le groupe {1} : cette option n'est pas une "
 "multi"
 
-#: tiramisu/option.py:896
+#: tiramisu/option.py:1175
 msgid "master group with wrong master name for {0}"
-msgstr "le groupe maître avec un nom de maître éroné pour {0}"
+msgstr "le groupe maître avec un nom de maître érroné pour {0}"
 
-#: tiramisu/option.py:905
+#: tiramisu/option.py:1184
 msgid "no child has same nom has master group for: {0}"
 msgstr "pas d'enfant avec le nom du groupe maître pour {0} "
 
-#: tiramisu/option.py:908
+#: tiramisu/option.py:1187
 msgid "group_type: {0} not allowed"
 msgstr "group_type : {0} non autorisé"
 
-#: tiramisu/option.py:946
+#: tiramisu/option.py:1277
 msgid "malformed requirements type for option: {0}, must be a dict"
 msgstr ""
 "type requirements malformé pour l'option : {0}, doit être un dictionnaire"
 
-#: tiramisu/option.py:962
+#: tiramisu/option.py:1294
 msgid ""
 "malformed requirements for option: {0} require must have option, expected "
 "and action keys"
 msgstr ""
 "requirements malformé pour l'option : {0} l'exigence doit avoir les clefs "
-"option, exptected et action"
+"option, expected et action"
 
-#: tiramisu/option.py:967
+#: tiramisu/option.py:1299
 msgid "malformed requirements for option: {0} inverse must be boolean"
-msgstr "requirements malformé pour l'option : {0} inverse doit être un booléen"
+msgstr ""
+"requirements mal formés pour l'option : {0} inverse doit être un booléen"
 
-#: tiramisu/option.py:971
+#: tiramisu/option.py:1303
 msgid "malformed requirements for option: {0} transitive must be boolean"
-msgstr "requirements malformé pour l'option : {0} transitive doit être booléen"
+msgstr ""
+"requirements mal formés pour l'option : {0} transitive doit être booléen"
 
-#: tiramisu/option.py:975
+#: tiramisu/option.py:1307
 msgid "malformed requirements for option: {0} same_action must be boolean"
 msgstr ""
-"requirements malformé pour l'option : {0} same_action doit être un booléen"
+"requirements mal formés pour l'option : {0} same_action doit être un booléen"
 
-#: tiramisu/option.py:979
+#: tiramisu/option.py:1311
 msgid "malformed requirements must be an option in option {0}"
-msgstr "requirements malformé doit être une option dans l'option {0}"
+msgstr "requirements mal formés doit être une option dans l'option {0}"
 
-#: tiramisu/option.py:982
+#: tiramisu/option.py:1314
 msgid "malformed requirements option {0} should not be a multi"
-msgstr "requirements malformé l'option {0} ne doit pas être une multi"
+msgstr "requirements mal formés l'option {0} ne doit pas être une multi"
 
-#: tiramisu/option.py:988
+#: tiramisu/option.py:1320
 msgid ""
 "malformed requirements second argument must be valid for option {0}: {1}"
 msgstr ""
-"requirements malformé deuxième argument doit être valide pour l'option {0} : "
-"{1}"
+"requirements mal formés deuxième argument doit être valide pour l'option "
+"{0} : {1}"
 
-#: tiramisu/option.py:993
+#: tiramisu/option.py:1325
 msgid "inconsistency in action types for option: {0} action: {1}"
 msgstr "incohérence dans les types action pour l'option : {0} action {1}"
 
-#: tiramisu/setting.py:47
-msgid "storage_type is already set, cannot rebind it"
-msgstr "storage_type est déjà défini, impossible de le redéfinir"
+#: tiramisu/option.py:1350
+msgid "{0} should be a function"
+msgstr "{0} doit être une fonction"
 
-#: tiramisu/setting.py:67
+#: tiramisu/option.py:1353
+msgid "{0}_params should be a dict"
+msgstr "{0}_params devrait être un dict"
+
+#: tiramisu/option.py:1356
+msgid "{0}_params with key {1} should not have length different to 1"
+msgstr ""
+"{0}_params avec la clef {1} devrait ne pas avoir une longueur différent de 1"
+
+#: tiramisu/option.py:1360
+msgid "{0}_params should be tuple for key \"{1}\""
+msgstr "{0}_params devrait être un tuple pour la clef \"{1}\""
+
+#: tiramisu/option.py:1366
+msgid "validator not support tuple"
+msgstr "validator n'accepte pas de tuple"
+
+#: tiramisu/option.py:1369
+msgid "{0}_params should have an option not a {0} for first argument"
+msgstr "{0}_params devrait avoir une option pas un {0} pour premier argument"
+
+#: tiramisu/option.py:1373
+msgid "{0}_params should have a boolean not a {0} for second argument"
+msgstr "{0}_params devrait avoir un boolean pas un {0} pour second argument"
+
+#: tiramisu/setting.py:116
 msgid "can't rebind {0}"
 msgstr "ne peut redéfinir ({0})"
 
-#: tiramisu/setting.py:72
+#: tiramisu/setting.py:121
 msgid "can't unbind {0}"
 msgstr "ne peut supprimer ({0})"
 
-#: tiramisu/setting.py:185
+#: tiramisu/setting.py:259
 msgid "cannot append {0} property for option {1}: this property is calculated"
 msgstr ""
 "ne peut ajouter la propriété {0} dans l'option {1}: cette propriété est "
 "calculée"
 
-#: tiramisu/setting.py:215
-msgid "option {0} not already exists in storage {1}"
-msgstr "option {0} n'existe pas dans l'espace de stockage {1}"
-
-#: tiramisu/setting.py:282
+#: tiramisu/setting.py:322
 msgid "opt and all_properties must not be set together in reset"
 msgstr "opt et all_properties ne doit pas être renseigné ensemble dans reset"
 
-#: tiramisu/setting.py:297
+#: tiramisu/setting.py:337
 msgid "if opt is not None, path should not be None in _getproperties"
 msgstr ""
 "si opt n'est pas None, path devrait ne pas être à None dans _getproperties"
 
-#: tiramisu/setting.py:391
+#: tiramisu/setting.py:440
 msgid "cannot change the value for option {0} this option is frozen"
 msgstr ""
-"ne peut modifié la valeur de l'option {0} cette option n'est pas modifiable"
+"ne peut modifier la valeur de l'option {0} cette option n'est pas modifiable"
 
-#: tiramisu/setting.py:397
+#: tiramisu/setting.py:446
 msgid "trying to access to an option named: {0} with properties {1}"
 msgstr "tentative d'accès à une option nommée : {0} avec les propriétés {1}"
 
-#: tiramisu/setting.py:415
+#: tiramisu/setting.py:464
 msgid "permissive must be a tuple"
 msgstr "permissive doit être un tuple"
 
-#: tiramisu/setting.py:422 tiramisu/value.py:277
+#: tiramisu/setting.py:471 tiramisu/value.py:301
 msgid "invalid generic owner {0}"
 msgstr "invalide owner générique {0}"
 
-#: tiramisu/setting.py:503
+#: tiramisu/setting.py:558
 msgid ""
 "malformed requirements imbrication detected for option: '{0}' with "
 "requirement on: '{1}'"
 msgstr ""
-"imbrication de requirements malformé detectée pour l'option : '{0}' avec "
+"imbrication de requirements mal formés detectée pour l'option : '{0}' avec "
 "requirement sur : '{1}'"
 
-#: tiramisu/setting.py:515
+#: tiramisu/setting.py:570
 msgid "option '{0}' has requirement's property error: {1} {2}"
 msgstr "l'option '{0}' a une erreur de propriété pour le requirement : {1} {2}"
 
-#: tiramisu/storage/dictionary/storage.py:37
+#: tiramisu/storage/__init__.py:52
+msgid "storage_type is already set, cannot rebind it"
+msgstr "storage_type est déjà défini, impossible de le redéfinir"
+
+#: tiramisu/storage/__init__.py:86
+msgid "option {0} not already exists in storage {1}"
+msgstr "option {0} n'existe pas dans l'espace de stockage {1}"
+
+#: tiramisu/storage/dictionary/storage.py:39
 msgid "dictionary storage cannot delete session"
 msgstr ""
 "impossible de supprimer une session dans un espace de stockage dictionary"
 
-#: tiramisu/storage/dictionary/storage.py:46
+#: tiramisu/storage/dictionary/storage.py:50
 msgid "session already used"
 msgstr "session déjà utilisée"
 
-#: tiramisu/storage/dictionary/storage.py:48
+#: tiramisu/storage/dictionary/storage.py:52
 msgid "a dictionary cannot be persistent"
 msgstr "un espace de stockage dictionary ne peut être persistant"
 
-#: tiramisu/value.py:284
+#: tiramisu/value.py:308
 msgid "no value for {0} cannot change owner to {1}"
 msgstr "pas de valeur pour {0} ne peut changer d'utilisateur pour {1}"
 
-#: tiramisu/value.py:356
+#: tiramisu/value.py:416
 msgid "invalid len for the slave: {0} which has {1} as master"
 msgstr "longueur invalide pour une esclave : {0} qui a {1} comme maître"
 
-#: tiramisu/value.py:373
+#: tiramisu/value.py:440
 msgid "invalid len for the master: {0} which has {1} as slave with greater len"
 msgstr ""
 "longueur invalide pour un maître : {0} qui a {1} une esclave avec une plus "
 "grande longueur"
 
-#: tiramisu/value.py:394
+#: tiramisu/value.py:470
 msgid "cannot append a value on a multi option {0} which is a slave"
 msgstr "ne peut ajouter une valeur sur l'option multi {0} qui est une esclave"
 
-#: tiramisu/value.py:429
+#: tiramisu/value.py:507
 msgid "cannot sort multi option {0} if master or slave"
 msgstr "ne peut trier une option multi {0} pour une maître ou une esclave"
 
-#: tiramisu/value.py:433
+#: tiramisu/value.py:511
 msgid "cmp is not permitted in python v3 or greater"
 msgstr "cmp n'est pas permis en python v3 ou supérieure"
 
-#: tiramisu/value.py:442
+#: tiramisu/value.py:520
 msgid "cannot reverse multi option {0} if master or slave"
 msgstr "ne peut inverser une option multi {0} pour une maître ou une esclave"
 
-#: tiramisu/value.py:450
+#: tiramisu/value.py:528
 msgid "cannot insert multi option {0} if master or slave"
 msgstr "ne peut insérer une option multi {0} pour une maître ou une esclave"
 
-#: tiramisu/value.py:458
+#: tiramisu/value.py:536
 msgid "cannot extend multi option {0} if master or slave"
 msgstr "ne peut étendre une option multi {0} pour une maître ou une esclave"
 
-#: tiramisu/value.py:482
+#: tiramisu/value.py:564
 msgid "cannot pop a value on a multi option {0} which is a slave"
 msgstr "ne peut supprimer une valeur dans l'option multi {0} qui est esclave"
 
+#~ msgid "validator should return a boolean, not {0}"
+#~ msgstr "le validator devrait retourner un boolean, pas un {0}"
+
+#~ msgid "invalid value {0} for option {1} for object {2}"
+#~ msgstr "valeur invalide {0} pour l'option {1} pour l'objet {2}"
+
+#~ msgid "no config specified but needed"
+#~ msgstr "aucune config spécifié alors que c'est nécessaire"
+
+#~ msgid "{0} has no attribute impl_set_information"
+#~ msgstr "{0} n'a pas d'attribut impl_set_information"
+
+#~ msgid "{0} has no attribute impl_get_information"
+#~ msgstr "{0} n'a pas d'attribut impl_get_information"
+
+#~ msgid "invalid name: {0} for optiondescription"
+#~ msgstr "nom invalide : {0} pour l'optiondescription"
+
 #~ msgid "metaconfig's children must be a list"
 #~ msgstr "enfants d'une metaconfig doit être une liste"
 
diff --git a/translations/tiramisu.pot b/translations/tiramisu.pot
index ef40426..dfd4b86 100644
--- a/translations/tiramisu.pot
+++ b/translations/tiramisu.pot
@@ -5,7 +5,7 @@
 msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
-"POT-Creation-Date: 2013-09-02 11:30+CEST\n"
+"POT-Creation-Date: 2013-09-26 22:33+CEST\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -15,395 +15,423 @@ msgstr ""
 "Generated-By: pygettext.py 1.5\n"
 
 
-#: tiramisu/autolib.py:58
-msgid "no config specified but needed"
-msgstr ""
-
-#: tiramisu/autolib.py:65
+#: tiramisu/autolib.py:145
 msgid "unable to carry out a calculation, option {0} has properties: {1} for: {2}"
 msgstr ""
 
-#: tiramisu/autolib.py:74
+#: tiramisu/autolib.py:154
 msgid "unable to carry out a calculation, option value with multi types must have same length for: {0}"
 msgstr ""
 
-#: tiramisu/config.py:47
+#: tiramisu/config.py:52
 msgid "descr must be an optiondescription, not {0}"
 msgstr ""
 
-#: tiramisu/config.py:121
+#: tiramisu/config.py:127
 msgid "unknown group_type: {0}"
 msgstr ""
 
-#: tiramisu/config.py:157
+#: tiramisu/config.py:163
 msgid "no option description found for this config (may be metaconfig without meta)"
 msgstr ""
 
-#: tiramisu/config.py:311
+#: tiramisu/config.py:189
+msgid "can't assign to an OptionDescription"
+msgstr ""
+
+#: tiramisu/config.py:320
 msgid "unknown type_ type {0}for _find"
 msgstr ""
 
-#: tiramisu/config.py:350
+#: tiramisu/config.py:359
 msgid "no option found in config with these criteria"
 msgstr ""
 
-#: tiramisu/config.py:400
+#: tiramisu/config.py:409
 msgid "make_dict can't filtering with value without option"
 msgstr ""
 
-#: tiramisu/config.py:421
+#: tiramisu/config.py:430
 msgid "unexpected path {0}, should start with {1}"
 msgstr ""
 
-#: tiramisu/config.py:481
+#: tiramisu/config.py:490
 msgid "opt in getowner must be an option not {0}"
 msgstr ""
 
-#: tiramisu/option.py:71
-msgid "{0} has no attribute impl_set_information"
-msgstr ""
-
-#: tiramisu/option.py:86
-msgid "information's item not found: {0}"
-msgstr ""
-
-#: tiramisu/option.py:89
-msgid "{0} has no attribute impl_get_information"
-msgstr ""
-
-#: tiramisu/option.py:117
-msgid "'{0}' ({1}) object attribute '{2}' is read-only"
-msgstr ""
-
-#: tiramisu/option.py:208
+#: tiramisu/option.py:70
 msgid "invalid name: {0} for option"
 msgstr ""
 
-#: tiramisu/option.py:218
-msgid "validator must be a function"
-msgstr ""
-
-#: tiramisu/option.py:225
-msgid "a default_multi is set whereas multi is False in option: {0}"
-msgstr ""
-
-#: tiramisu/option.py:231
-msgid "invalid default_multi value {0} for option {1}: {2}"
-msgstr ""
-
-#: tiramisu/option.py:236
-msgid "default value not allowed if option: {0} is calculated"
-msgstr ""
-
-#: tiramisu/option.py:239
-msgid "params defined for a callback function but no callback defined yet for option {0}"
-msgstr ""
-
-#: tiramisu/option.py:261 tiramisu/option.py:809
+#: tiramisu/option.py:80
 msgid "invalid properties type {0} for {1}, must be a tuple"
 msgstr ""
 
-#: tiramisu/option.py:334
-msgid "invalid value {0} for option {1} for object {2}"
+#: tiramisu/option.py:122
+msgid "'{0}' ({1}) object attribute '{2}' is read-only"
 msgstr ""
 
-#: tiramisu/option.py:342 tiramisu/value.py:468
+#: tiramisu/option.py:149 tiramisu/value.py:362
+msgid "information's item not found: {0}"
+msgstr ""
+
+#: tiramisu/option.py:266
+msgid "cannot serialize Option, only in OptionDescription"
+msgstr ""
+
+#: tiramisu/option.py:367
+msgid "a default_multi is set whereas multi is False in option: {0}"
+msgstr ""
+
+#: tiramisu/option.py:373
+msgid "invalid default_multi value {0} for option {1}: {2}"
+msgstr ""
+
+#: tiramisu/option.py:378
+msgid "default value not allowed if option: {0} is calculated"
+msgstr ""
+
+#: tiramisu/option.py:381
+msgid "params defined for a callback function but no callback defined yet for option {0}"
+msgstr ""
+
+#: tiramisu/option.py:486 tiramisu/value.py:547
 msgid "invalid value {0} for option {1}: {2}"
 msgstr ""
 
-#: tiramisu/option.py:354
+#: tiramisu/option.py:506
 msgid "invalid value {0} for option {1} which must be a list"
 msgstr ""
 
-#: tiramisu/option.py:423
+#: tiramisu/option.py:577
 msgid "invalid value {0} for option {1} must be different as {2} option"
 msgstr ""
 
-#: tiramisu/option.py:445
+#: tiramisu/option.py:636
 msgid "values must be a tuple for {0}"
 msgstr ""
 
-#: tiramisu/option.py:448
+#: tiramisu/option.py:639
 msgid "open_values must be a boolean for {0}"
 msgstr ""
 
-#: tiramisu/option.py:469
+#: tiramisu/option.py:661
 msgid "value {0} is not permitted, only {1} is allowed"
 msgstr ""
 
-#: tiramisu/option.py:481
+#: tiramisu/option.py:673
 msgid "value must be a boolean"
 msgstr ""
 
-#: tiramisu/option.py:491
+#: tiramisu/option.py:683
 msgid "value must be an integer"
 msgstr ""
 
-#: tiramisu/option.py:501
+#: tiramisu/option.py:693
 msgid "value must be a float"
 msgstr ""
 
-#: tiramisu/option.py:511
+#: tiramisu/option.py:703
 msgid "value must be a string, not {0}"
 msgstr ""
 
-#: tiramisu/option.py:529
+#: tiramisu/option.py:721
 msgid "value must be an unicode"
 msgstr ""
 
-#: tiramisu/option.py:539
+#: tiramisu/option.py:733
 msgid "malformed symlinkoption must be an option for symlink {0}"
 msgstr ""
 
-#: tiramisu/option.py:581
-msgid "IP shall not be in reserved class"
+#: tiramisu/option.py:788
+msgid "invalid IP {0}"
 msgstr ""
 
-#: tiramisu/option.py:583
+#: tiramisu/option.py:793
+msgid "IP mustn't not be in reserved class"
+msgstr ""
+
+#: tiramisu/option.py:795
 msgid "IP must be in private class"
 msgstr ""
 
-#: tiramisu/option.py:621
+#: tiramisu/option.py:833
 msgid "inconsistency in allowed range"
 msgstr ""
 
-#: tiramisu/option.py:626
+#: tiramisu/option.py:838
 msgid "max value is empty"
 msgstr ""
 
-#: tiramisu/option.py:663
+#: tiramisu/option.py:877
+msgid "invalid network address {0}"
+msgstr ""
+
+#: tiramisu/option.py:882
 msgid "network shall not be in reserved class"
 msgstr ""
 
-#: tiramisu/option.py:695
+#: tiramisu/option.py:894
+msgid "invalid netmask address {0}"
+msgstr ""
+
+#: tiramisu/option.py:916
 msgid "invalid network {0} ({1}) with netmask {2} ({3}), this network is an IP"
 msgstr ""
 
-#: tiramisu/option.py:700
+#: tiramisu/option.py:921
 msgid "invalid IP {0} ({1}) with netmask {2} ({3}), this IP is a network"
 msgstr ""
 
-#: tiramisu/option.py:705
+#: tiramisu/option.py:926
 msgid "invalid IP {0} ({1}) with netmask {2} ({3})"
 msgstr ""
 
-#: tiramisu/option.py:707
+#: tiramisu/option.py:928
 msgid "invalid network {0} ({1}) with netmask {2} ({3})"
 msgstr ""
 
-#: tiramisu/option.py:727
+#: tiramisu/option.py:939
+msgid "invalid broadcast address {0}"
+msgstr ""
+
+#: tiramisu/option.py:957
 msgid "unknown type_ {0} for hostname"
 msgstr ""
 
-#: tiramisu/option.py:730
+#: tiramisu/option.py:960
 msgid "allow_ip must be a boolean"
 msgstr ""
 
-#: tiramisu/option.py:759
+#: tiramisu/option.py:990
 msgid "invalid value for {0}, must have dot"
 msgstr ""
 
-#: tiramisu/option.py:762
+#: tiramisu/option.py:993
 msgid "invalid domainname's length for {0} (max {1})"
 msgstr ""
 
-#: tiramisu/option.py:765
+#: tiramisu/option.py:996
 msgid "invalid domainname's length for {0} (min 2)"
 msgstr ""
 
-#: tiramisu/option.py:769
+#: tiramisu/option.py:1000
 msgid "invalid domainname"
 msgstr ""
 
-#: tiramisu/option.py:787
-msgid "invalid name: {0} for optiondescription"
-msgstr ""
-
-#: tiramisu/option.py:799
+#: tiramisu/option.py:1027
 msgid "duplicate option name: {0}"
 msgstr ""
 
-#: tiramisu/option.py:825
+#: tiramisu/option.py:1044
 msgid "unknown Option {0} in OptionDescription {1}"
 msgstr ""
 
-#: tiramisu/option.py:874
+#: tiramisu/option.py:1095
 msgid "duplicate option: {0}"
 msgstr ""
 
-#: tiramisu/option.py:904
+#: tiramisu/option.py:1129
 msgid "no option for path {0}"
 msgstr ""
 
-#: tiramisu/option.py:910
+#: tiramisu/option.py:1135
 msgid "no option {0} found"
 msgstr ""
 
-#: tiramisu/option.py:920
+#: tiramisu/option.py:1145
 msgid "cannot change group_type if already set (old {0}, new {1})"
 msgstr ""
 
-#: tiramisu/option.py:933
+#: tiramisu/option.py:1158
 msgid "master group {0} shall not have a subgroup"
 msgstr ""
 
-#: tiramisu/option.py:936
+#: tiramisu/option.py:1161
 msgid "master group {0} shall not have a symlinkoption"
 msgstr ""
 
-#: tiramisu/option.py:939
+#: tiramisu/option.py:1164
 msgid "not allowed option {0} in group {1}: this option is not a multi"
 msgstr ""
 
-#: tiramisu/option.py:950
+#: tiramisu/option.py:1175
 msgid "master group with wrong master name for {0}"
 msgstr ""
 
-#: tiramisu/option.py:959
+#: tiramisu/option.py:1184
 msgid "no child has same nom has master group for: {0}"
 msgstr ""
 
-#: tiramisu/option.py:962
+#: tiramisu/option.py:1187
 msgid "group_type: {0} not allowed"
 msgstr ""
 
-#: tiramisu/option.py:1021
+#: tiramisu/option.py:1277
 msgid "malformed requirements type for option: {0}, must be a dict"
 msgstr ""
 
-#: tiramisu/option.py:1037
+#: tiramisu/option.py:1294
 msgid "malformed requirements for option: {0} require must have option, expected and action keys"
 msgstr ""
 
-#: tiramisu/option.py:1042
+#: tiramisu/option.py:1299
 msgid "malformed requirements for option: {0} inverse must be boolean"
 msgstr ""
 
-#: tiramisu/option.py:1046
+#: tiramisu/option.py:1303
 msgid "malformed requirements for option: {0} transitive must be boolean"
 msgstr ""
 
-#: tiramisu/option.py:1050
+#: tiramisu/option.py:1307
 msgid "malformed requirements for option: {0} same_action must be boolean"
 msgstr ""
 
-#: tiramisu/option.py:1054
+#: tiramisu/option.py:1311
 msgid "malformed requirements must be an option in option {0}"
 msgstr ""
 
-#: tiramisu/option.py:1057
+#: tiramisu/option.py:1314
 msgid "malformed requirements option {0} should not be a multi"
 msgstr ""
 
-#: tiramisu/option.py:1063
+#: tiramisu/option.py:1320
 msgid "malformed requirements second argument must be valid for option {0}: {1}"
 msgstr ""
 
-#: tiramisu/option.py:1068
+#: tiramisu/option.py:1325
 msgid "inconsistency in action types for option: {0} action: {1}"
 msgstr ""
 
-#: tiramisu/setting.py:47
-msgid "storage_type is already set, cannot rebind it"
+#: tiramisu/option.py:1350
+msgid "{0} should be a function"
 msgstr ""
 
-#: tiramisu/setting.py:67
+#: tiramisu/option.py:1353
+msgid "{0}_params should be a dict"
+msgstr ""
+
+#: tiramisu/option.py:1356
+msgid "{0}_params with key {1} should not have length different to 1"
+msgstr ""
+
+#: tiramisu/option.py:1360
+msgid "{0}_params should be tuple for key \"{1}\""
+msgstr ""
+
+#: tiramisu/option.py:1366
+msgid "validator not support tuple"
+msgstr ""
+
+#: tiramisu/option.py:1369
+msgid "{0}_params should have an option not a {0} for first argument"
+msgstr ""
+
+#: tiramisu/option.py:1373
+msgid "{0}_params should have a boolean not a {0} for second argument"
+msgstr ""
+
+#: tiramisu/setting.py:116
 msgid "can't rebind {0}"
 msgstr ""
 
-#: tiramisu/setting.py:72
+#: tiramisu/setting.py:121
 msgid "can't unbind {0}"
 msgstr ""
 
-#: tiramisu/setting.py:185
+#: tiramisu/setting.py:259
 msgid "cannot append {0} property for option {1}: this property is calculated"
 msgstr ""
 
-#: tiramisu/setting.py:215
-msgid "option {0} not already exists in storage {1}"
-msgstr ""
-
-#: tiramisu/setting.py:282
+#: tiramisu/setting.py:322
 msgid "opt and all_properties must not be set together in reset"
 msgstr ""
 
-#: tiramisu/setting.py:297
+#: tiramisu/setting.py:337
 msgid "if opt is not None, path should not be None in _getproperties"
 msgstr ""
 
-#: tiramisu/setting.py:391
+#: tiramisu/setting.py:440
 msgid "cannot change the value for option {0} this option is frozen"
 msgstr ""
 
-#: tiramisu/setting.py:397
+#: tiramisu/setting.py:446
 msgid "trying to access to an option named: {0} with properties {1}"
 msgstr ""
 
-#: tiramisu/setting.py:415
+#: tiramisu/setting.py:464
 msgid "permissive must be a tuple"
 msgstr ""
 
-#: tiramisu/setting.py:422 tiramisu/value.py:277
+#: tiramisu/setting.py:471 tiramisu/value.py:301
 msgid "invalid generic owner {0}"
 msgstr ""
 
-#: tiramisu/setting.py:503
+#: tiramisu/setting.py:558
 msgid "malformed requirements imbrication detected for option: '{0}' with requirement on: '{1}'"
 msgstr ""
 
-#: tiramisu/setting.py:515
+#: tiramisu/setting.py:570
 msgid "option '{0}' has requirement's property error: {1} {2}"
 msgstr ""
 
-#: tiramisu/storage/dictionary/storage.py:37
+#: tiramisu/storage/__init__.py:52
+msgid "storage_type is already set, cannot rebind it"
+msgstr ""
+
+#: tiramisu/storage/__init__.py:86
+msgid "option {0} not already exists in storage {1}"
+msgstr ""
+
+#: tiramisu/storage/dictionary/storage.py:39
 msgid "dictionary storage cannot delete session"
 msgstr ""
 
-#: tiramisu/storage/dictionary/storage.py:46
+#: tiramisu/storage/dictionary/storage.py:50
 msgid "session already used"
 msgstr ""
 
-#: tiramisu/storage/dictionary/storage.py:48
+#: tiramisu/storage/dictionary/storage.py:52
 msgid "a dictionary cannot be persistent"
 msgstr ""
 
-#: tiramisu/value.py:284
+#: tiramisu/value.py:308
 msgid "no value for {0} cannot change owner to {1}"
 msgstr ""
 
-#: tiramisu/value.py:356
+#: tiramisu/value.py:416
 msgid "invalid len for the slave: {0} which has {1} as master"
 msgstr ""
 
-#: tiramisu/value.py:373
+#: tiramisu/value.py:440
 msgid "invalid len for the master: {0} which has {1} as slave with greater len"
 msgstr ""
 
-#: tiramisu/value.py:394
+#: tiramisu/value.py:470
 msgid "cannot append a value on a multi option {0} which is a slave"
 msgstr ""
 
-#: tiramisu/value.py:429
+#: tiramisu/value.py:507
 msgid "cannot sort multi option {0} if master or slave"
 msgstr ""
 
-#: tiramisu/value.py:433
+#: tiramisu/value.py:511
 msgid "cmp is not permitted in python v3 or greater"
 msgstr ""
 
-#: tiramisu/value.py:442
+#: tiramisu/value.py:520
 msgid "cannot reverse multi option {0} if master or slave"
 msgstr ""
 
-#: tiramisu/value.py:450
+#: tiramisu/value.py:528
 msgid "cannot insert multi option {0} if master or slave"
 msgstr ""
 
-#: tiramisu/value.py:458
+#: tiramisu/value.py:536
 msgid "cannot extend multi option {0} if master or slave"
 msgstr ""
 
-#: tiramisu/value.py:482
+#: tiramisu/value.py:564
 msgid "cannot pop a value on a multi option {0} which is a slave"
 msgstr ""