Hi, I'll try to checkpoint the discussion had so far. As Krzysztof is planning to serve more than one VO with the same service, we cannot have a one to one relationship between entityIDs and VOs, this imply the need of having a VO attribute. Which was also more or less David's concern, an authority being able to assert whatever it wants. If we go wiht this, the VO attribute stays. We have two proposal so far. Tom suggested to use the MACE-Dir eduPersonScopedAffiliation attribute <saml:Attribute xmlns:xacmlprof="urn:oasis:names:tc:SAML:2.0:profiles:attribute:XACML" xmlns:ldapprof="urn:oasis:names:tc:SAML:2.0:profiles:attribute:LDAP" xacmlprof:DataType="http://www.w3.org/2001/XMLSchema#string" ldapprof:Encoding="LDAP" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri" Name="urn:oid:1.3.6.1.4.1.5923.1.1.1.9" FriendlyName="eduPersonScopedAffiliation"> <saml:AttributeValue xsi:type="xs:string">member@voName </saml:AttributeValue> </saml:Attribute> while in our first draft Krzysztof and I suggested the use of a specific <saml:Attribute xmlns:xacmlprof="urn:oasis:names:tc:SAML:2.0:profiles:attribute:XACML" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri" Name="uri_to_define" FriendlyName="vo" xacmlprof:DataType="http://www.w3.org/2001/XMLSchema#string"> <saml:AttributeValue xsi:type="xsd:string"> voName </saml:AttributeValue> </saml:Attribute> Let's try to agree on one. There were concerns about Tom's proposal to use Grouper to express groups, specifically about the contents being an URN. Anyway, the specification doesn't mandate them to be URN, it recommends to use URIs is uniqueness is to eb achieved. Other concerns with using this? Still we have no suggestions for expressing roles, apart from the initial (but I have made the group syntax homogeneous with the above) <saml:Attribute xmlns:xacmlprof="urn:oasis:names:tc:SAML:2.0:profiles:attribute:XACML" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri" Name="uri_to_define" FriendlyName="role" xacmlprof:DataType="http://www.w3.org/2001/XMLSchema#string"> <saml:AttributeValue xsi:type="xsd:string"> VO-Admin@vo </saml:AttributeValue> <saml:AttributeValue xsi:type="xsd:string"> SoftwareManager@vo:group:subgroup </saml:AttributeValue> </saml:Attribute> that seems to receive more favor than the one with the scope attributes. What problems can you see with that? Valerio