diff --git a/product/ERP5Type/Accessor/TypeDefinition.py b/product/ERP5Type/Accessor/TypeDefinition.py
index 798ecabe0a8c2eb1ec7dc5a598eca893ebc0bf4b..27ddf6f635502b4cd69ed35f91883b65d2a5b5a3 100644
--- a/product/ERP5Type/Accessor/TypeDefinition.py
+++ b/product/ERP5Type/Accessor/TypeDefinition.py
@@ -142,12 +142,15 @@ type_definition = {
                              'default' : [],
                              'isList'  : 1,
                            },
-    'content'             : { 'cast'    : identity,
+                           # Content are subdocuments (ex. default_career)
+    'content'             : { 'cast'    : identity,          
                              'null'    : ('', 'None', None,),
                              'default' : None,
                              'isList'  : 0,
                            },
-    'object'             : { 'cast'    : identity,
+                           # Object are properties of any type (ex. data)
+                           # and are considered as simple properties
+    'object'             : { 'cast'    : identity, 
                              'null'    : ('', 'None', None,),
                              'default' : None,
                              'isList'  : 0,