diff --git a/configure.zcml b/configure.zcml
index 017c533..bb85de0 100644
--- a/configure.zcml
+++ b/configure.zcml
@@ -406,6 +406,11 @@
       component="loops.type.TypeInterfaceSourceList"
       name="loops.TypeInterfaceSource" />
 
+  <utility
+      provides="zope.schema.interfaces.IVocabularyFactory"
+      component="loops.predicate.PredicateInterfaceSourceList"
+      name="loops.PredicateInterfaceSource" />
+
 
   <include package=".browser" />
   <include package=".classifier" />
diff --git a/interfaces.py b/interfaces.py
index 330534f..8fdf8dd 100644
--- a/interfaces.py
+++ b/interfaces.py
@@ -620,7 +620,7 @@ class ITypeConcept(IConceptSchema):
         description=_(u'An interface that objects of this type can '
                         'be adapted to'),
         default=None,
-        source="loops.TypeInterfaceSource",
+        source='loops.TypeInterfaceSource',
         required=False)
 
     viewName = schema.TextLine(
@@ -645,13 +645,13 @@ class IPredicate(IConceptSchema):
         i.e. concepts of type 'predicate' should be adaptable to this interface.
     """
 
-    typeInterface = schema.TextLine(    #schema.Choice
-        title=_(u'Type Interface'),
+    predicateInterface = schema.Choice(
+        title=_(u'Predicate Interface'),
         description=_(u'Optional: allows specification of additional '
                     'attributes of relations that are instances of this '
                     'predicate.'),
-        default=u'',    #None
-        #source="loops.TypeInterfaceSource",
+        default=None,
+        source='loops.PredicateInterfaceSource',
         required=False)
 
 
diff --git a/organize/README.txt b/organize/README.txt
index b6a789e..5bc74ff 100644
--- a/organize/README.txt
+++ b/organize/README.txt
@@ -355,6 +355,16 @@ Events listing
   >>> list(listing.events())
   [<loops.browser.concept.ConceptRelationView ...>]
 
+Allocation of persons to tasks
+------------------------------
+
+  >>> from loops.organize.interfaces import IAllocated
+  >>> predicate = concepts['predicate']
+  >>> allocated = addAndConfigureObject(concepts, Concept, 'allocated',
+  ...                   title=u'allocated',
+  ...                   conceptType=predicate, predicateInterface=IAllocated)
+
+
 
 Fin de partie
 =============
diff --git a/organize/interfaces.py b/organize/interfaces.py
index 04600c6..97fb115 100644
--- a/organize/interfaces.py
+++ b/organize/interfaces.py
@@ -34,6 +34,7 @@ from cybertools.organize.interfaces import IPerson as IBasePerson
 from cybertools.organize.interfaces import ITask
 from loops.interfaces import IConceptSchema
 from loops.organize.util import getPrincipalFolder
+from loops import util
 from loops.util import _
 
 ANNOTATION_KEY = 'loops.organize.person'
@@ -141,7 +142,7 @@ class IMemberRegistrationManager(Interface):
     """
 
     authPluginId = Attribute(u'The id of an authentication plugin to be '
-                              'used for managing members of this loops site')
+                             u'used for managing members of this loops site')
 
     def register(userId, password, lastName, firstName=u'', **kw):
         """ Register a new member for this loops site.
@@ -161,3 +162,18 @@ class ITask(IConceptSchema, ITask):
 
     pass
 
+
+# 'allocated' predicate
+
+class IAllocated(Interface):
+
+    allocType = schema.Choice(
+            title=_(u'Allocation Type'),
+            description=_(u'Specifies the kind of interaction a person or another '
+                    u'party has with the task or project it is allocated to.'),
+            source=util.KeywordVocabulary((
+                    ('standard', _(u'Standard')),
+                    ('master', _(u'Master')),
+                )),
+            default='standard',
+            required=True)
diff --git a/organize/party.py b/organize/party.py
index 78cb2e1..022600a 100644
--- a/organize/party.py
+++ b/organize/party.py
@@ -40,16 +40,18 @@ from cybertools.typology.interfaces import IType
 from loops.common import AdapterBase
 from loops.concept import Concept
 from loops.interfaces import IConcept
-from loops.organize.interfaces import IAddress
-from loops.organize.interfaces import IPerson, ANNOTATION_KEY
+from loops.organize.interfaces import IAddress, IPerson, IAllocated
+from loops.organize.interfaces import ANNOTATION_KEY
 from loops.security.common import assignOwner, removeOwner, allowEditingForOwner
 from loops.type import TypeInterfaceSourceList
+from loops.predicate import PredicateInterfaceSourceList
 from loops import util
 
 
 # register type interfaces - (TODO: use a function for this)
 
 TypeInterfaceSourceList.typeInterfaces += (IPerson, IAddress)
+PredicateInterfaceSourceList.typeInterfaces += (IAllocated,)
 
 
 def getPersonForUser(context, request=None, principal=None):
diff --git a/organize/setup.py b/organize/setup.py
index 80d46a1..92abcff 100644
--- a/organize/setup.py
+++ b/organize/setup.py
@@ -46,6 +46,9 @@ class SetupManager(BaseSetupManager):
 
         owner = self.addObject(concepts, Concept, 'ownedby', title=u'owned by',
                         conceptType=predicate)
+        #allocated = self.addAndConfigureObject(concepts, Concept, 'allocated',
+        #                title=u'allocated',
+        #                conceptType=predicate, predicateInterface=IAllocated)
 
         task = self.addAndConfigureObject(concepts, Concept, 'task', title=u'Task',
                         conceptType=type, typeInterface=ITask)
diff --git a/predicate.py b/predicate.py
index a789d92..3bdb722 100644
--- a/predicate.py
+++ b/predicate.py
@@ -34,10 +34,10 @@ from loops.interfaces import ILoopsObject, IConcept, IResource
 from loops.interfaces import IPredicate
 from loops.concept import Concept
 from loops.common import AdapterBase
-from loops.type import TypeInterfaceSourceList as BaseTypeInterfaceSourceList
+from loops.type import TypeInterfaceSourceList
 
 
-BaseTypeInterfaceSourceList.typeInterfaces += (IPredicate,)
+TypeInterfaceSourceList.typeInterfaces += (IPredicate,)
 
 
 class Predicate(AdapterBase):
@@ -49,7 +49,7 @@ class Predicate(AdapterBase):
     _contextAttributes = list(IPredicate) + list(IConcept)
 
 
-class TypeInterfaceSourceList(BaseTypeInterfaceSourceList):
+class PredicateInterfaceSourceList(TypeInterfaceSourceList):
     """ Collects type interfaces for predicates, i.e. interfaces that
         may be used for specifying additional attributes of relations.
     """