use RichString

schema.py

-from cubicweb.schema import format_constraint
+from cubicweb.schema import RichString
 
 class Basket(MetaUserEntityType):
     """a basket contains a set of other entities"""
@@ -11,9 +11,7 @@ class Basket(MetaUserEntityType):
 
     name = String(required=True, indexed=True, internationalizable=True,
                   maxsize=128)
-    description_format = String(meta=True, internationalizable=True, maxsize=50,
-                                default='text/rest', constraints=[format_constraint])
-    description = String(fulltextindexed=True)
+    description = RichString(fulltextindexed=True)
 
     in_basket = ObjectRelation('*')