--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pyams_content/reference/interfaces/__init__.py	Sat Mar 10 02:35:15 2018 +0100
@@ -0,0 +1,42 @@
+#
+# Copyright (c) 2008-2015 Thierry Florac <tflorac AT ulthar.net>
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+
+__docformat__ = 'restructuredtext'
+
+
+# import standard library
+
+# import interfaces
+from pyams_content.interfaces import IBaseContent
+from zope.container.interfaces import IContainer
+
+# import packages
+from zope.container.constraints import containers, contains
+
+
+class IReferenceInfo(IBaseContent):
+    """Base reference interface"""
+
+    containers('.IReferenceTable')
+
+
+class IReferenceTable(IBaseContent):
+    """Reference table interface"""
+
+    containers('.IReferenceTableContainer')
+    contains(IReferenceInfo)
+
+
+class IReferenceManager(IBaseContent, IContainer):
+    """References tables container"""
+
+    contains(IReferenceTable)