diff --git a/trytond/ir/action.py b/trytond/ir/action.py
index 816986f8c7..92ea0aff91 100644
--- a/trytond/ir/action.py
+++ b/trytond/ir/action.py
@@ -46,15 +46,6 @@ class ActionKeyword(OSV):
     "Action keyword"
     _name = 'ir.action.keyword'
     _description = __doc__
-
-    def _models_get(self, cursor, user, context=None):
-        model_obj = self.pool.get('ir.model')
-        model_ids = model_obj.search(cursor, user, [])
-        res = []
-        for model in model_obj.browse(cursor, user, model_ids, context=context):
-            res.append([model.model, model.name])
-        return res
-
     _columns = {
         'keyword': fields.Selection([
             ('tree_open', 'Open tree'),
@@ -63,7 +54,7 @@ class ActionKeyword(OSV):
             ('form_action', 'Action form'),
             ('form_relate', 'Form relate'),
             ], string='Keyword', required=True),
-        'model': fields.Reference('Model', selection=_models_get, size=128),
+        'model': fields.Reference('Model', selection='models_get', size=128),
         'action': fields.many2one('ir.action', 'Action',
             ondelete='CASCADE'),
     }
@@ -76,6 +67,14 @@ class ActionKeyword(OSV):
                     vals['action'], context=context)
         return vals
 
+    def models_get(self, cursor, user, context=None):
+        model_obj = self.pool.get('ir.model')
+        model_ids = model_obj.search(cursor, user, [])
+        res = []
+        for model in model_obj.browse(cursor, user, model_ids, context=context):
+            res.append([model.model, model.name])
+        return res
+
     def unlink(self, cursor, user, ids, context=None):
         for keyword in self.browse(cursor, user, ids, context=context):
             # Restart the cache view
diff --git a/trytond/ir/property.py b/trytond/ir/property.py
index adaf90846e..23e5b338f1 100644
--- a/trytond/ir/property.py
+++ b/trytond/ir/property.py
@@ -6,8 +6,16 @@ class Property(OSV):
     "Property"
     _name = 'ir.property'
     _description = __doc__
+    _columns = {
+        'name': fields.char('Name', size=128),
+        'value': fields.reference('Value', selection='models_get2', size=128),
+        'res_id': fields.reference('Resource', selection='models_get', size=128),
+        #'company_id': fields.many2one('res.company', 'Company'),
+        'fields_id': fields.many2one('ir.model.fields', 'Fields',
+            ondelete='cascade', required=True)
+    }
 
-    def _models_get2(self, cursor, user, context=None):
+    def models_get2(self, cursor, user, context=None):
         model_fields_obj = self.pool.get('ir.model.fields')
         ids = model_fields_obj.search(cursor, user, [('view_load', '=', 1)])
         res = []
@@ -19,7 +27,7 @@ class Property(OSV):
                 done[model_field.relation] = True
         return res
 
-    def _models_get(self, cursor, user, context=None):
+    def models_get(self, cursor, user, context=None):
         model_fields_obj = self.pool.get('ir.model.fields')
         ids = model_fields_obj.search(cursor, user, [('view_load', '=', 1)])
         res = []
@@ -32,15 +40,6 @@ class Property(OSV):
                 done[model_field.model_id.id] = True
         return res
 
-    _columns = {
-        'name': fields.char('Name', size=128),
-        'value': fields.reference('Value', selection=_models_get2, size=128),
-        'res_id': fields.reference('Resource', selection=_models_get, size=128),
-        #'company_id': fields.many2one('res.company', 'Company'),
-        'fields_id': fields.many2one('ir.model.fields', 'Fields',
-            ondelete='cascade', required=True)
-    }
-
     def unlink(self, cursor, user, ids, context=None):
         if ids:
             cursor.execute('DELETE FROM ir_model_fields ' \
diff --git a/trytond/ir/rule.py b/trytond/ir/rule.py
index 24ac1b1a0f..54f5c2543a 100644
--- a/trytond/ir/rule.py
+++ b/trytond/ir/rule.py
@@ -56,8 +56,24 @@ class Rule(OSV):
     _name = 'ir.rule'
     _rec_name = 'field_id'
     _description = __doc__
+    _columns = {
+        'field_id': fields.many2one('ir.model.fields', 'Field',
+            domain="[('model_id','=', parent.model_id)]", select=1,
+            required=True),
+        'operator':fields.selection([
+            ('=', '='),
+            ('<>', '<>'),
+            ('<=', '<='),
+            ('>=', '>='),
+            ('in', 'in'),
+            ('child_of', 'child_of'),
+            ], 'Operator', required=True),
+        'operand':fields.selection('operand','Operand', size=64, required=True),
+        'rule_group': fields.many2one('ir.rule.group', 'Group', select=2,
+            required=True, ondelete="cascade")
+    }
 
-    def _operand(self, cursor, user, context):
+    def operand(self, cursor, user, context):
 
         def get(obj_name, level=3, recur=None, root_tech='', root=''):
             res = []
@@ -93,23 +109,6 @@ class Rule(OSV):
                 recur=['many2one'], root_tech='user', root='User')
         return res
 
-    _columns = {
-        'field_id': fields.many2one('ir.model.fields', 'Field',
-            domain="[('model_id','=', parent.model_id)]", select=1,
-            required=True),
-        'operator':fields.selection([
-            ('=', '='),
-            ('<>', '<>'),
-            ('<=', '<='),
-            ('>=', '>='),
-            ('in', 'in'),
-            ('child_of', 'child_of'),
-            ], 'Operator', required=True),
-        'operand':fields.selection(_operand,'Operand', size=64, required=True),
-        'rule_group': fields.many2one('ir.rule.group', 'Group', select=2,
-            required=True, ondelete="cascade")
-    }
-
     def domain_get(self, cursor, user, model_name):
         # root user above constraint
         if user == 1:
diff --git a/trytond/ir/sequence.py b/trytond/ir/sequence.py
index f4c0ac0a60..530cdb80c5 100644
--- a/trytond/ir/sequence.py
+++ b/trytond/ir/sequence.py
@@ -18,14 +18,9 @@ class Sequence(OSV):
     "Sequence"
     _name = 'ir.sequence'
     _description = __doc__
-
-    def _code_get(self, cursor, user, context=None):
-        cursor.execute('select code, name from ir_sequence_type')
-        return cursor.fetchall()
-
     _columns = {
         'name': fields.char('Sequence Name',size=64, required=True),
-        'code': fields.selection(_code_get, 'Sequence Code',size=64,
+        'code': fields.selection('code_get', 'Sequence Code',size=64,
             required=True),
         'active': fields.boolean('Active'),
         'prefix': fields.char('Prefix',size=64),
@@ -41,6 +36,10 @@ class Sequence(OSV):
         'padding' : lambda *a : 0,
     }
 
+    def code_get(self, cursor, user, context=None):
+        cursor.execute('select code, name from ir_sequence_type')
+        return cursor.fetchall()
+
     def _process(self, string):
         return (string or '') % {
                 'year':time.strftime('%Y'),
diff --git a/trytond/ir/translation.py b/trytond/ir/translation.py
index 3a41d94541..c51b47acc4 100644
--- a/trytond/ir/translation.py
+++ b/trytond/ir/translation.py
@@ -30,13 +30,6 @@ class Translation(OSV, Cacheable):
     _name = "ir.translation"
     _description = __doc__
 
-    def _get_language(self, cursor, user, context):
-        lang_obj = self.pool.get('ir.lang')
-        lang_ids = lang_obj.search(cursor, user, [], context=context)
-        langs = lang_obj.browse(cursor, user, lang_ids, context=context)
-        res = [(lang.code, lang.name) for lang in langs]
-        return res
-
     def _model(self, cursor, user, ids, name, arg, context=None):
         res = {}
         for translation in self.browse(cursor, user, ids, context=context):
@@ -57,7 +50,7 @@ class Translation(OSV, Cacheable):
     _columns = {
         'name': fields.Char('Field Name', size=128, required=True),
         'res_id': fields.Integer('Resource ID'),
-        'lang': fields.Selection(_get_language, string='Language', size=5),
+        'lang': fields.Selection('get_language', string='Language', size=5),
         'type': fields.Selection(TRANSLATION_TYPE, string='Type', size=16,
             required=True),
         'src': fields.Text('Source'),
@@ -79,6 +72,13 @@ class Translation(OSV, Cacheable):
         CREATE INDEX ir_translation_res_id ON ir_translation (res_id);
     """
 
+    def get_language(self, cursor, user, context):
+        lang_obj = self.pool.get('ir.lang')
+        lang_ids = lang_obj.search(cursor, user, [], context=context)
+        langs = lang_obj.browse(cursor, user, lang_ids, context=context)
+        res = [(lang.code, lang.name) for lang in langs]
+        return res
+
     def _get_ids(self, cursor, name, ttype, lang, ids):
         translations, to_fetch = {}, []
         if name.split(',')[0] == 'ir.model.fields':
@@ -364,8 +364,12 @@ class TranslationUpdateInit(WizardOSV):
     "Update translation - language"
     _name = 'ir.translation.update.init'
     _description = __doc__
+    _columns = {
+        'lang': fields.Selection('get_language', string='Language', size=5,
+            required=True),
+    }
 
-    def _get_language(self, cursor, user, context):
+    def get_language(self, cursor, user, context):
         lang_obj = self.pool.get('ir.lang')
         lang_ids = lang_obj.search(cursor, user, [('translatable', '=', True)],
                 context=context)
@@ -373,11 +377,6 @@ class TranslationUpdateInit(WizardOSV):
         res = [(lang.code, lang.name) for lang in langs if lang.code != 'en_US']
         return res
 
-    _columns = {
-        'lang': fields.Selection(_get_language, string='Language', size=5,
-            required=True),
-    }
-
 TranslationUpdateInit()
 
 
@@ -489,15 +488,21 @@ class TranslationExportInit(WizardOSV):
     "Export translation - language and module"
     _name = 'ir.translation.export.init'
     _description = __doc__
+    _columns = {
+        'lang': fields.Selection('get_language', string='Language', size=5,
+            required=True),
+        'module': fields.Selection('get_module', string='Module', size=128,
+            required=True),
+    }
 
-    def _get_language(self, cursor, user, context):
+    def get_language(self, cursor, user, context):
         lang_obj = self.pool.get('ir.lang')
         lang_ids = lang_obj.search(cursor, user, [], context=context)
         langs = lang_obj.browse(cursor, user, lang_ids, context=context)
         res = [(lang.code, lang.name) for lang in langs]
         return res
 
-    def _get_module(self, cursor, user, context):
+    def get_module(self, cursor, user, context):
         module_obj = self.pool.get('ir.module.module')
         module_ids = module_obj.search(cursor, user, [], context=context)
         modules = module_obj.browse(cursor, user, module_ids, context=context)
@@ -505,13 +510,6 @@ class TranslationExportInit(WizardOSV):
                 for module in modules]
         return res
 
-    _columns = {
-        'lang': fields.Selection(_get_language, string='Language', size=5,
-            required=True),
-        'module': fields.Selection(_get_module, string='Module', size=128,
-            required=True),
-    }
-
 TranslationExportInit()
 
 
diff --git a/trytond/osv/fields.py b/trytond/osv/fields.py
index 5e6e3b71f8..ba95666090 100644
--- a/trytond/osv/fields.py
+++ b/trytond/osv/fields.py
@@ -184,6 +184,10 @@ class Selection(_column):
     _type = 'selection'
 
     def __init__(self, selections, string='unknown', **args):
+        """
+        selections is a list of (key, string)
+            or the name of the object function that return the list
+        """
         _column.__init__(self, string=string, **args)
         self.selection = selections
 
diff --git a/trytond/osv/orm.py b/trytond/osv/orm.py
index dd98afc893..7e5f576ac0 100644
--- a/trytond/osv/orm.py
+++ b/trytond/osv/orm.py
@@ -1376,8 +1376,9 @@ class ORM(object):
                                 'is not in the selection' % \
                                 (val, field))
                 else:
-                    if val not in dict(self._columns[field].selection(
-                        self, cursor, user, context=context)):
+                    if val not in dict(getattr(self,
+                        self._columns[field].selection)(
+                        cursor, user, context=context)):
                         raise ExceptORM('ValidateError',
                         'The value "%s" for the field "%s" ' \
                                 'is not in the selection' % \
@@ -1538,8 +1539,9 @@ class ORM(object):
                                 'is not in the selection' % \
                                 (val, field))
                 else:
-                    if val not in dict(self._columns[field].selection(
-                        self, cursor, user, context=context)):
+                    if val not in dict(getattr(self,
+                        self._columns[field].selection)(
+                        cursor, user, context=context)):
                         raise ExceptORM('ValidateError',
                         'The value "%s" for the field "%s" ' \
                                 'is not in the selection' % \
@@ -1627,8 +1629,7 @@ class ORM(object):
                     res[field]['selection'] = sel
                 else:
                     # call the 'dynamic selection' function
-                    res[field]['selection'] = self._columns[field].selection(
-                            self, cursor, user, context)
+                    res[field]['selection'] = self._columns[field].selection
             if res[field]['type'] in (
                     'one2many',
                     'many2many',
diff --git a/trytond/res/request.py b/trytond/res/request.py
index 07e5bf2da6..f48be0c514 100644
--- a/trytond/res/request.py
+++ b/trytond/res/request.py
@@ -7,14 +7,6 @@ class Request(OSV):
     _name = 'res.request'
     _table = 'res_request'
     _description = __doc__
-
-    def _links_get(self, cursor, user, context=None):
-        request_link_obj = self.pool.get('res.request.link')
-        ids = request_link_obj.search(cursor, user, [])
-        request_links = request_link_obj.browse(cursor, user, ids,
-                context=context)
-        return [(x.object, x.name) for x in request_links]
-
     _columns = {
         'create_date': fields.DateTime('Created date', readonly=True),
         'name': fields.Char('Subject', states={
@@ -48,11 +40,11 @@ class Request(OSV):
 #                'closed': [('readonly', True)],
 #                }),
         #TODO: use one2many instead limit number of reference
-        'ref_doc1': fields.Reference('Document Ref 1', selection=_links_get,
+        'ref_doc1': fields.Reference('Document Ref 1', selection='links_get',
             size=128, states={
                 'readonly': "state == 'closed'",
                 }),
-        'ref_doc2': fields.Reference('Document Ref 2', selection=_links_get,
+        'ref_doc2': fields.Reference('Document Ref 2', selection='links_get',
             size=128, states={
                 'readonly': "state == 'closed'",
                 }),
@@ -73,6 +65,13 @@ class Request(OSV):
     }
     _order = 'priority DESC, trigger_date, create_date DESC'
 
+    def links_get(self, cursor, user, context=None):
+        request_link_obj = self.pool.get('res.request.link')
+        ids = request_link_obj.search(cursor, user, [])
+        request_links = request_link_obj.browse(cursor, user, ids,
+                context=context)
+        return [(x.object, x.name) for x in request_links]
+
     def request_send(self, cursor, user, ids, context=None):
         request_history_obj = self.pool.get('res.request.history')
         for request in self.browse(cursor, user, ids, context=context):
diff --git a/trytond/res/user.py b/trytond/res/user.py
index 5ac2f936b4..6b65bd7ca6 100644
--- a/trytond/res/user.py
+++ b/trytond/res/user.py
@@ -62,23 +62,6 @@ class User(OSV):
     _name = "res.user"
     _log_access = False
     _description = __doc__
-
-    def _languages(self, cursor, user, context=None):
-        lang_obj = self.pool.get('ir.lang')
-        lang_ids = lang_obj.search(cursor, user, [], context=context)
-        res = []
-        for lang in lang_obj.browse(cursor, user, lang_ids, context=context):
-            res.append([lang.code, lang.name])
-        return res
-
-    def _timezones(self, cursor, user, context=None):
-        try:
-            import pytz
-            res = [[x, x] for x in pytz.all_timezones]
-        except ImportError:
-            res = [[time.tzname[0], time.tzname[0]]]
-        return res
-
     _columns = {
         'name': fields.Char('Name', size=64, required=True, select=1),
         'login': fields.Char('Login', size=64, required=True),
@@ -96,8 +79,8 @@ class User(OSV):
         'rule_groups': fields.Many2Many('ir.rule.group', 'user_rule_group_rel',
             'user_id', 'rule_group_id', 'Rules',
             domain="[('global', '<>', True)]"),
-        'language': fields.Selection(_languages, 'Language'),
-        'timezone': fields.Selection(_timezones, 'Timezone'),
+        'language': fields.Selection('languages', 'Language'),
+        'timezone': fields.Selection('timezones', 'Timezone'),
     }
     _sql_constraints = [
         ('login_key', 'UNIQUE (login)',
@@ -214,6 +197,22 @@ class User(OSV):
         res['fields'] = fields
         return res
 
+    def languages(self, cursor, user, context=None):
+        lang_obj = self.pool.get('ir.lang')
+        lang_ids = lang_obj.search(cursor, user, [], context=context)
+        res = []
+        for lang in lang_obj.browse(cursor, user, lang_ids, context=context):
+            res.append([lang.code, lang.name])
+        return res
+
+    def timezones(self, cursor, user, context=None):
+        try:
+            import pytz
+            res = [[x, x] for x in pytz.all_timezones]
+        except ImportError:
+            res = [[time.tzname[0], time.tzname[0]]]
+        return res
+
 User()