diff --git a/tiramisu/storage/dictionary/option.py b/tiramisu/storage/dictionary/option.py
new file mode 100644
index 0000000..cdddce6
--- /dev/null
+++ b/tiramisu/storage/dictionary/option.py
@@ -0,0 +1,165 @@
+# -*- coding: utf-8 -*-
+""
+# Copyright (C) 2014 Team tiramisu (see AUTHORS for all contributors)
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# ____________________________________________________________
+from tiramisu.i18n import _
+from tiramisu.setting import groups
+
+
+#____________________________________________________________
+#
+# Base
+class Base(object):
+    __slots__ = ('_name', '_requires', '_properties', '_readonly',
+                 '_calc_properties', '_informations',
+                 '_state_readonly', '_state_requires', '_stated',
+                 '_multi', '_validator', '_validator_params', '_default',
+                 '_default_multi', '_state_callback', '_callback',
+                 '_callback_params', '_multitype', '_consistencies',
+                 '_warnings_only', '_master_slaves', '_state_consistencies',
+                 '_extra', '__weakref__')
+
+    def __init__(self):
+        try:
+            self._consistencies
+        except AttributeError:
+            self._consistencies = []
+        try:
+            self._callback
+        except AttributeError:
+            self._callback = None
+        try:
+            self._callback_params
+        except AttributeError:
+            self._callback_params = None
+        try:
+            self._validator
+        except AttributeError:
+            self._validator = None
+        try:
+            self._validator_params
+        except AttributeError:
+            self._validator_params = None
+
+    def _add_consistency(self, func, all_cons_opts):
+        self._consistencies.append((func, all_cons_opts))
+
+    def _get_consistencies(self):
+        return self._consistencies
+
+    def _get_id(self):
+        return id(self)
+
+
+class OptionDescription(Base):
+    __slots__ = ('_children', '_cache_paths', '_cache_consistencies',
+                 '_group_type', '_is_build_cache')
+
+    def __init__(self):
+        pass
+
+    def _add_children(self, child_names, children):
+        self._children = (tuple(child_names), tuple(children))
+
+    def impl_already_build_caches(self):
+        return self._is_build_cache
+
+    def impl_get_opt_by_path(self, path):
+        try:
+            return self._cache_paths[0][self._cache_paths[1].index(path)]
+        except ValueError:
+            raise AttributeError(_('no option for path {0}').format(path))
+
+    def impl_get_path_by_opt(self, opt):
+        try:
+            return self._cache_paths[1][self._cache_paths[0].index(opt)]
+        except ValueError:
+            raise AttributeError(_('no option {0} found').format(opt))
+
+    def impl_get_group_type(self):
+        return getattr(groups, self._group_type)
+
+    def impl_build_cache_option(self, _currpath=None, cache_path=None, cache_option=None):
+        if _currpath is None and self._cache_paths is not None:
+            # cache already set
+            return
+        if _currpath is None:
+            save = True
+            _currpath = []
+        else:
+            save = False
+        if cache_path is None:
+            cache_path = []
+            cache_option = []
+        for option in self.impl_getchildren():
+            attr = option._name
+            cache_option.append(option)
+            cache_path.append(str('.'.join(_currpath + [attr])))
+            if option.__class__.__name__ == 'OptionDescription':
+                _currpath.append(attr)
+                option.impl_build_cache_option(_currpath, cache_path,
+                                               cache_option)
+                _currpath.pop()
+        if save:
+            self._cache_paths = (tuple(cache_option), tuple(cache_path))
+
+    def impl_get_options_paths(self, bytype, byname, _subpath, only_first):
+        def _filter_by_name():
+            if byname is None or path == byname or \
+                    path.endswith('.' + byname):
+                return True
+            return False
+
+        def _filter_by_type():
+            if bytype is None:
+                return True
+            if isinstance(option, bytype):
+                return True
+            return False
+
+        find_results = []
+        opts, paths = self._cache_paths
+        for index in range(0, len(paths)):
+            option = opts[index]
+            if option.__class__.__name__ == 'OptionDescription':
+                continue
+            path = paths[index]
+            if _subpath is not None and not path.startswith(_subpath + '.'):
+                continue
+            if not _filter_by_name():
+                continue
+            if not _filter_by_type():
+                continue
+            retval = (path, option)
+            if only_first:
+                return retval
+            find_results.append(retval)
+        return find_results
+
+    def impl_getchildren(self):
+        return self._children[1]
+
+    def __getattr__(self, name):
+        if name == '_name':
+            return object.__getattribute__(self, name)
+        try:
+            return self._children[1][self._children[0].index(name)]
+        except ValueError:
+            raise AttributeError(_('unknown Option {0} '
+                                   'in OptionDescription {1}'
+                                   '').format(name, self._name))