diff --git a/src/rougail/output_formatter/__init__.py b/src/rougail/output_formatter/__init__.py
index d97362e..fe9b763 100644
--- a/src/rougail/output_formatter/__init__.py
+++ b/src/rougail/output_formatter/__init__.py
@@ -31,12 +31,11 @@ from ruamel.yaml.scalarstring import LiteralScalarString, FoldedScalarString, Sc
 from djlint.settings import Config
 from djlint.reformat import formatter
 
-from tiramisu import undefined
 from tiramisu.config import get_common_path
 
 from rougail.convert import RougailConvert
 from rougail.object_model import Variable, Family, Calculation, JinjaCalculation, IdentifierCalculation, IdentifierPropertyCalculation, NamespaceCalculation, IdentifierParam, IndexCalculation, IndexParam, NamespaceParam, Param
-from rougail.utils import normalize_family
+from rougail.utils import normalize_family, undefined
 
 from .upgrade import RougailUpgrade
 from .__version__ import __version__
@@ -82,25 +81,57 @@ class RougailOutputFormatter:
             from rougail import RougailConfig
             rougailconfig = RougailConfig
             rougailconfig["step.output"] = self.output_name
-        if rougailconfig["step.output"] != self.output_name:
+        self.rougailconfig = rougailconfig
+        if self.rougailconfig["step.output"] != self.output_name:
             raise ExtentionError(_('the "step.output" is not set to "{0}"').format(self.output_name))
         # yaml.top_level_colon_align = True
-        self.main_namespace = rougailconfig["main_namespace"]
-        filenames = rougailconfig["main_dictionaries"]
-        if len(rougailconfig["main_dictionaries"]) > 1:
+        self.main_namespace = normalize_family(self.rougailconfig["main_namespace"])
+        self.has_default_dictionary_format_version = self.rougailconfig["default_dictionary_format_version"] is not None
+        self.config = Config()
+        self.config.profile = 'jinja'
+        self.config.line_break_after_multiline_tag = True
+        self.config.indent = "  "
+        self.attributes = {}
+
+        self.yaml = YAML()
+
+    def run(self):
+        self.upgrade()
+        self.families = {self.main_namespace: CommentedMap()}
+        self.parse()
+        self.yaml.indent(mapping=2, sequence=4, offset=2)
+        self.yaml.version = '1.2'
+        self.yaml.explicit_start = True
+        self.yaml.explicit_end = True
+        self.default_flow_style = False
+        with BytesIO() as ymlfh:
+            families = self.families[self.main_namespace]
+            if not families:
+                self.yaml.dump('', ymlfh)
+            else:
+                self.yaml.dump(families, ymlfh)
+            ret = ymlfh.getvalue().decode("utf-8").strip()
+        return True, ret
+
+    def get_attributes(self, obj, excludes=[]) -> dict:
+        type_name = obj.__name__
+        if type_name == 'Variable' and excludes == []:
+            raise Exception('pff')
+        if type_name not in self.attributes:
+            self.attributes[type_name] = {str(attr): o.default for attr, o in obj.model_fields.items() if str(attr) not in excludes}
+        return self.attributes[type_name]
+
+    def upgrade(self) -> None:
+        filenames = self.rougailconfig["main_dictionaries"]
+        if len(filenames) > 1:
             raise Exception(_('only one file is allowed'))
         filename = Path(filenames[0])
         if not filename.is_file():
             raise Exception(_('only a file is allowed'))
 
-        self.config = Config()
-        self.config.profile = 'jinja'
-        self.config.line_break_after_multiline_tag = True
-        self.config.indent = "  "
-
-        self.original_yaml = RougailUpgrade(rougailconfig).run(filename)
-        datas = RougailUpgrade(rougailconfig).run(filename)
-        self.rougail = RougailConvert(rougailconfig)
+        self.version_name, self.original_yaml = RougailUpgrade(self.rougailconfig).run(filename)
+        self.version_name, datas = RougailUpgrade(self.rougailconfig).run(filename)
+        self.rougail = RougailConvert(self.rougailconfig)
         self.rougail.load_config()
         self.rougail.init()
         self.filename_str = str(filename)
@@ -119,23 +150,6 @@ class RougailOutputFormatter:
             "1.1",
             datas,
         )
-        self.yaml = YAML()
-
-    def run(self):
-        self.families_attributes = {attr: obj.get("default") for attr, obj in self.rougail.family.model_json_schema()["properties"].items()}
-        self.dynamics_attributes = {attr: obj.get("default") for attr, obj in self.rougail.dynamic.model_json_schema()["properties"].items()}
-        self.variables_attributes = {attr: obj.get("default") for attr, obj in self.rougail.variable.model_json_schema()["properties"].items()}
-        self.families = {None: CommentedMap()}
-        self.parse()
-        self.yaml.indent(mapping=2, sequence=4, offset=2)
-        self.yaml.version = '1.2'
-        self.yaml.explicit_start = True
-        self.yaml.explicit_end = True
-        self.default_flow_style = False
-        with BytesIO() as ymlfh:
-            self.yaml.dump(self.families[None], ymlfh)
-            ret = ymlfh.getvalue().decode("utf-8").strip()
-        return True, ret
 
     def print(self):
         ret, data = self.run()
@@ -143,33 +157,21 @@ class RougailOutputFormatter:
         return ret
 
     def parse(self):
-        # FIXME path to relative !
-        if self.rougail.namespace:
-            version_path = f'{self.rougail.namespace}.version'
-        else:
-            version_path = 'version'
-        if version_path in self.rougail.paths._data:
-            version_name = '_version'
-        else:
-            version_name = 'version'
-        self.families[None][version_name] = None
-        self.families[None].yaml_value_comment_extend(version_name, [CommentToken('\n\n', CommentMark(0)), None])
-        version = None
+        self.families[self.main_namespace][self.version_name] = float(self.rougail.version)
         self.remaining = len(self.rougail.paths._data)
         for path, obj in self.rougail.paths._data.items():
             self.remaining -= 1
-            if version is None or version == '':
-                version = obj.version
             if path == self.rougail.namespace:
-                self.families[path] = self.families[None]
+#                self.families[path] = self.families[None]
                 continue
             if isinstance(obj, Family):
                 self.parse_family(path, obj)
             if isinstance(obj, Variable):
                 self.parse_variable(path, obj)
-        if not version:
-            raise Exception(_(f'no variables in file {self.filename_str}'))
-        self.families[None][version_name] = float(version)
+        if list(self.families[self.main_namespace]) != [self.version_name]:
+            self.families[self.main_namespace].yaml_value_comment_extend(self.version_name, [CommentToken('\n\n', CommentMark(0)), None])
+        if self.has_default_dictionary_format_version:
+            del self.families[self.main_namespace][self.version_name]
 
     def parse_family(self, path, obj):
         children = [p.rsplit('.', 1)[-1] for p in self.rougail.parents[path]]
@@ -187,9 +189,9 @@ class RougailOutputFormatter:
                 force_keys = list(yaml_data)
         type_ = obj.type
         if type_ == "dynamic":
-            attributes = self.dynamics_attributes
+            attributes = self.get_attributes(self.rougail.dynamic)
         else:
-            attributes = self.families_attributes
+            attributes = self.get_attributes(self.rougail.family)
         for attr, default_value in attributes.items():
             if attr in ["name", "path", "namespace", "version", "xmlfiles"]:
                 continue
@@ -244,9 +246,7 @@ class RougailOutputFormatter:
                 force_keys = list(yaml_data)
         multi = obj.multi or isinstance(obj.default, list)
         type_ = obj.type
-        for attr, default_value in self.variables_attributes.items():
-            if attr in ["name", "path", "namespace", "version", "xmlfiles"]:
-                continue
+        for attr, default_value in self.get_attributes(self.rougail.variable, ["name", "path", "namespace", "version", "xmlfiles"]).items():
             try:
                 value = getattr(obj, attr)
             except AttributeError:
@@ -372,12 +372,15 @@ class RougailOutputFormatter:
             if value.return_type:
                 jinja["return_type"] = value.return_type
             if value.description:
-                jinja["description"] = value.description
+                if '\n' in value.description:
+                    jinja["description"] = LiteralScalarString(value.description)
+                else:
+                    jinja["description"] = value.description
             if value.params:
                 jinja["params"] = self.object_to_yaml("params", type_, value.params, multi, object_path)
             return jinja
         elif isinstance(value, Calculation):
-            variable_attributes = self.get_object_informations(value, ['path', 'inside_list', 'version', 'xmlfiles', 'attribute_name', 'namespace'])
+            variable_attributes = self.get_attributes(value.__class__, ['path', 'inside_list', 'version', 'xmlfiles', 'attribute_name', 'namespace'])
             variable = CommentedMap()
             if isinstance(value, (IdentifierCalculation, IdentifierPropertyCalculation)):
                 variable["type"] = "identifier"
@@ -393,9 +396,14 @@ class RougailOutputFormatter:
                 variable["variable"] = self.calc_variable_path(object_path, variable["variable"])
             if variable.get('type') == 'identifier' and 'identifier' in variable:
                 del variable["type"]
+            if value.description:
+                if '\n' in value.description:
+                    variable["description"] = LiteralScalarString(value.description)
+                else:
+                    variable["description"] = value.description
             return variable
         elif isinstance(value, Param):
-            param_attributes = self.get_object_informations(value, ["type", "key", "namespace"])
+            param_attributes = self.get_attributes(value.__class__, ["type", "key", "namespace"])
             if list(param_attributes) == ['value']:
                 variable = value.value
             else:
@@ -434,9 +442,6 @@ class RougailOutputFormatter:
                 return "_" * (relative_object_path.count(".") + 1) + '.' + variable_path[len_common_path:]
         return variable_path
 
-    def get_object_informations(self, value, excludes=[]):
-        return {attr: obj.get("default") for attr, obj in value.__class__.model_json_schema()["properties"].items() if attr not in excludes}
-
     def get_parent_name(self, path):
         if "." in path:
             return path.rsplit(".", 1)
diff --git a/src/rougail/output_formatter/upgrade.py b/src/rougail/output_formatter/upgrade.py
index f44c9f0..17c7f19 100644
--- a/src/rougail/output_formatter/upgrade.py
+++ b/src/rougail/output_formatter/upgrade.py
@@ -45,22 +45,33 @@ class RougailUpgrade:
 
     def run(
         self,
-        file,
-    ):
+        file: str,
+    ) -> dict:
         with file.open() as file_fh:
             root = YAML().load(file_fh)
-        search_function_name = get_function_name(str(root["version"]))
+        if not root:
+            root = {}
+        if '_version' in root:
+            version_name = '_version'
+            format_version = str(root.pop('_version'))
+        elif 'version' in root:
+            version_name = 'version'
+            format_version = str(root.pop('version'))
+        else:
+            version_name = None
+            format_version = self.rougailconfig["default_dictionary_format_version"]
+        if format_version not in VERSIONS:
+            raise Exception(f'version "{format_version}" is not a valid version')
+        search_function_name = get_function_name(format_version)
         function_found = False
         for version, function_version in FUNCTION_VERSIONS:
             if function_found and hasattr(self, function_version):
                 root = getattr(self, function_version)(root)
             if function_version == search_function_name:
                 function_found = True
-        if '_version' in root:
-            root["_version"] = float(version)
-        elif 'version' in root:
-            root["version"] = float(version)
-        return root
+        if version_name:
+            root[version_name] = float(version)
+        return version_name, root
 
     def update_1_1(
         self,
diff --git a/tests/results/00_0no_variable/rougail/00-base.yml b/tests/results/00_0no_variable/rougail/00-base.yml
new file mode 100644
index 0000000..94a82bd
--- /dev/null
+++ b/tests/results/00_0no_variable/rougail/00-base.yml
@@ -0,0 +1,4 @@
+%YAML 1.2
+---
+version: 1.1
+...
diff --git a/tests/results/00_0no_variable_default_version/rougail/00-base.yml b/tests/results/00_0no_variable_default_version/rougail/00-base.yml
new file mode 100644
index 0000000..ee52480
--- /dev/null
+++ b/tests/results/00_0no_variable_default_version/rougail/00-base.yml
@@ -0,0 +1,3 @@
+%YAML 1.2
+---
+...
diff --git a/tests/results/00_0no_variable_remove_version/rougail/00-base.yml b/tests/results/00_0no_variable_remove_version/rougail/00-base.yml
new file mode 100644
index 0000000..ee52480
--- /dev/null
+++ b/tests/results/00_0no_variable_remove_version/rougail/00-base.yml
@@ -0,0 +1,3 @@
+%YAML 1.2
+---
+...
diff --git a/tests/results/00_2default_calculated_params_permissive/rougail/00-base.yml b/tests/results/00_2default_calculated_params_permissive/rougail/00-base.yml
new file mode 100644
index 0000000..b389034
--- /dev/null
+++ b/tests/results/00_2default_calculated_params_permissive/rougail/00-base.yml
@@ -0,0 +1,22 @@
+%YAML 1.2
+---
+version: 1.1
+
+leadership:
+  type: leadership
+  hidden: true
+
+  var1:  # a first variable
+    - a_value
+
+  var2: a_value  # a first variable
+
+var2:
+  description: a second variable
+  default:
+    jinja: >-
+      {{ var1[0] }}
+    params:
+      var1:
+        variable: _.leadership.var1
+...
diff --git a/tests/results/00_2default_calculated_variable_description/rougail/00-base.yml b/tests/results/00_2default_calculated_variable_description/rougail/00-base.yml
new file mode 100644
index 0000000..f5948c3
--- /dev/null
+++ b/tests/results/00_2default_calculated_variable_description/rougail/00-base.yml
@@ -0,0 +1,12 @@
+%YAML 1.2
+---
+version: 1.1
+
+var1:  # a first variable
+
+var2:
+  description: a second variable
+  default:
+    variable: _.var1
+    description: value of a variable!
+...
diff --git a/tests/results/40_6leadership_follower_multi_no_mandatory/rougail/00-base.yml b/tests/results/40_6leadership_follower_multi_no_mandatory/rougail/00-base.yml
new file mode 100644
index 0000000..c6e1353
--- /dev/null
+++ b/tests/results/40_6leadership_follower_multi_no_mandatory/rougail/00-base.yml
@@ -0,0 +1,18 @@
+%YAML 1.2
+---
+version: 1.1
+
+leadership:
+  description: A leadership
+  type: leadership
+
+  leader:
+    description: The leader
+    multi: true
+    mandatory: false
+
+  follower1: []  # The first follower
+
+  follower2:  # The second follower
+    - value
+...
diff --git a/tests/results/60_5family_dynamic_calc_suffix_hidden/rougail/00-base.yml b/tests/results/60_5family_dynamic_calc_suffix_hidden/rougail/00-base.yml
new file mode 100644
index 0000000..b5ea488
--- /dev/null
+++ b/tests/results/60_5family_dynamic_calc_suffix_hidden/rougail/00-base.yml
@@ -0,0 +1,25 @@
+%YAML 1.2
+---
+version: 1.1
+
+var1:
+  description: A suffix variable
+  default:
+    - val1
+    - val2
+  mandatory: false
+
+dyn{{ identifier }}:
+  dynamic:
+    variable: _.var1
+
+  var:
+    description: A dynamic variable
+    default: a value
+    hidden: true
+
+var2:
+  description: A variable calculated
+  default:
+    variable: _.dynval1.var
+...
diff --git a/tests/results/60_5family_dynamic_calc_suffix_hidden_boolean/rougail/00-base.yml b/tests/results/60_5family_dynamic_calc_suffix_hidden_boolean/rougail/00-base.yml
new file mode 100644
index 0000000..510b4d9
--- /dev/null
+++ b/tests/results/60_5family_dynamic_calc_suffix_hidden_boolean/rougail/00-base.yml
@@ -0,0 +1,25 @@
+%YAML 1.2
+---
+version: 1.1
+
+var1:
+  description: A suffix variable
+  default:
+    - val1
+    - val2
+  mandatory: false
+
+dyn{{ identifier }}:
+  dynamic:
+    variable: _.var1
+
+  var:
+    description: A dynamic variable
+    default: true
+    hidden: true
+
+var2:
+  description: A variable calculated
+  default:
+    variable: _.dynval1.var
+...
diff --git a/tests/results/60_5family_dynamic_calc_suffix_hidden_multi/rougail/00-base.yml b/tests/results/60_5family_dynamic_calc_suffix_hidden_multi/rougail/00-base.yml
new file mode 100644
index 0000000..616d73f
--- /dev/null
+++ b/tests/results/60_5family_dynamic_calc_suffix_hidden_multi/rougail/00-base.yml
@@ -0,0 +1,27 @@
+%YAML 1.2
+---
+version: 1.1
+
+var1:
+  description: A suffix variable
+  default:
+    - val1
+    - val2
+  mandatory: false
+
+dyn{{ identifier }}:
+  dynamic:
+    variable: _.var1
+
+  var:
+    description: A dynamic variable
+    default:
+      - a value
+      - a second value
+    hidden: true
+
+var2:
+  description: A variable calculated
+  default:
+    variable: _.dynval1.var
+...