diff --git a/tabellio/documents/document.py b/tabellio/documents/document.py
index 388d6cc..e941ecb 100644
--- a/tabellio/documents/document.py
+++ b/tabellio/documents/document.py
@@ -46,7 +46,10 @@ class IDocument(form.Schema):
     adoption_date = schema.Date(title=_(u'Adoption Date'), required=False)
     moniteur_date = schema.Date(title=_(u'Moniteur Date'), required=False)
 
-    adopted = schema.Bool(title=_(u'Adopted'), required=False, default=False) # reserved for PFB
+    # reserved for PFB
+    adopted = schema.Bool(title=_(u'Adopted'), required=False, default=False)
+    related_docs = RelationList(title=_(u'Related Documents'), default=[], required=False,
+                    value_type=RelationChoice(title=_(u'Related Document'), source=ObjPathSourceBinder()))
 
 class Document(Item, BasePublication):
     implements(IDocument, IHasRelations)