diff --git a/test/test_option_setting.py b/test/test_option_setting.py
index f77fa8e..74993c2 100644
--- a/test/test_option_setting.py
+++ b/test/test_option_setting.py
@@ -308,3 +308,59 @@ def test_access_by_get_whith_hide():
     c = Config(descr)
     c.read_write()
     raises(AttributeError, "c.find(byname='b1')")
+
+
+def test_append_properties():
+    descr = make_description()
+    cfg = Config(descr)
+    setting = cfg.cfgimpl_get_settings()
+    option = cfg.cfgimpl_get_description().gc.dummy
+    assert option._properties == tuple()
+    assert not 'test' in setting[option]
+    setting[option].append('test')
+    assert option._properties == tuple()
+    assert 'test' in setting[option]
+
+
+def test_reset_properties():
+    descr = make_description()
+    cfg = Config(descr)
+    setting = cfg.cfgimpl_get_settings()
+    option = cfg.cfgimpl_get_description().gc.dummy
+    assert setting._properties == {}
+    setting.append('frozen')
+    assert setting._properties == {None: set(('frozen', 'expire', 'validator'))}
+    setting.reset()
+    assert setting._properties == {}
+    setting[option].append('test')
+    assert setting._properties == {option: set(('test',))}
+    setting.reset()
+    assert setting._properties == {option: set(('test',))}
+    setting.append('frozen')
+    assert setting._properties == {None: set(('frozen', 'expire', 'validator')), option: set(('test',))}
+    setting.reset(option)
+    assert setting._properties == {None: set(('frozen', 'expire', 'validator'))}
+    setting[option].append('test')
+    assert setting._properties == {None: set(('frozen', 'expire', 'validator')), option: set(('test',))}
+    setting.reset(all_properties=True)
+    assert setting._properties == {}
+    raises(ValueError, 'setting.reset(all_properties=True, opt=option)')
+
+
+def test_reset_multiple():
+    descr = make_description()
+    cfg = Config(descr)
+    setting = cfg.cfgimpl_get_settings()
+    option = cfg.cfgimpl_get_description().gc.dummy
+    setting.append('frozen')
+    setting[option].append('test')
+    setting.reset()
+    setting.reset()
+    setting.append('frozen')
+    setting[option].append('test')
+    setting.reset(option)
+    setting.reset(option)
+    setting.append('frozen')
+    setting[option].append('test')
+    setting.reset(all_properties=True)
+    setting.reset(all_properties=True)
diff --git a/tiramisu/option.py b/tiramisu/option.py
index 8a1804c..94d1aa1 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -170,7 +170,7 @@ class Option(BaseInformation):
         if not isinstance(properties, tuple):
             raise TypeError(_('invalid properties type {0} for {1},'
                             ' must be a tuple').format(type(properties), self._name))
-        self._properties = set(properties)  # 'hidden', 'disabled'...
+        self._properties = properties  # 'hidden', 'disabled'...
 
     def __eq__(self, other):
         "Option comparison"
@@ -728,7 +728,7 @@ class OptionDescription(BaseInformation):
         if not isinstance(properties, tuple):
             raise TypeError(_('invalid properties type {0} for {1},'
                               ' must be a tuple').format(type(properties), self._name))
-        self._properties = set(properties)  # 'hidden', 'disabled'...
+        self._properties = properties  # 'hidden', 'disabled'...
         # the group_type is useful for filtering OptionDescriptions in a config
         self._group_type = groups.default
 
diff --git a/tiramisu/setting.py b/tiramisu/setting.py
index d6537ef..f381f26 100644
--- a/tiramisu/setting.py
+++ b/tiramisu/setting.py
@@ -26,13 +26,13 @@ from tiramisu.error import RequirementError, PropertiesOptionError
 from tiramisu.i18n import _
 
 default_encoding = 'utf-8'
-
 expires_time = 5
 ro_remove = ('permissive', 'hidden')
 ro_append = ('frozen', 'disabled', 'validator', 'everything_frozen', 'mandatory')
 rw_remove = ('permissive', 'everything_frozen', 'mandatory')
 rw_append = ('frozen', 'disabled', 'validator', 'hidden')
-default_properties = set(('expire', 'validator'))
+default_properties = ('expire', 'validator')
+
 
 class _const:
     """convenient class that emulates a module
@@ -159,13 +159,14 @@ class Property(object):
     def append(self, propname):
         self._properties.add(propname)
         self._setting._set_properties(self._properties, self._opt)
-        self._setting.context.cfgimpl_reset_cache()
 
     def remove(self, propname):
         if propname in self._properties:
             self._properties.remove(propname)
             self._setting._set_properties(self._properties, self._opt)
-            self._setting.context.cfgimpl_reset_cache()
+
+    def reset(self):
+        self._setting.reset(opt=self._opt)
 
     def __contains__(self, propname):
         return propname in self._properties
@@ -204,16 +205,22 @@ class Setting(object):
     def __setitem__(self, opt, value):
         raise ValueError('you must only append/remove properties')
 
-    def reset(self):
-        try:
-            del(self._properties[None])
-        except KeyError:
-            pass
+    def reset(self, opt=None, all_properties=False):
+        if all_properties and opt:
+            raise ValueError(_('opt and all_properties must not be set '
+                               'together in reset'))
+        if all_properties:
+            self._properties = {}
+        else:
+            try:
+                del(self._properties[opt])
+            except KeyError:
+                pass
         self.context.cfgimpl_reset_cache()
 
     def _get_properties(self, opt=None, is_apply_req=True):
         if opt is None:
-            props = self._properties.get(opt, copy(default_properties))
+            props = self._properties.get(opt, set(default_properties))
         else:
             exp = None
             if opt in self._cache:
@@ -223,7 +230,7 @@ class Setting(object):
                     return props
             if is_apply_req:
                 self.apply_requires(opt)
-            props = self._properties.get(opt, opt._properties)
+            props = self._properties.get(opt, set(opt._properties))
             self._set_cache(opt, props, exp)
         return props
 
@@ -242,11 +249,12 @@ class Setting(object):
         if opt is None:
             self._properties[opt] = properties
         else:
-            if opt._properties == properties:
+            if set(opt._properties) == properties:
                 if opt in self._properties:
                     del(self._properties[opt])
             else:
                 self._properties[opt] = properties
+        self.context.cfgimpl_reset_cache()
 
     #____________________________________________________________
     def validate_properties(self, opt_or_descr, is_descr, is_write,