OID value: 1.3.6.1.4.1.5923.1.5.2.1
OID description:
An auxiliary object class, "eduMember," is a convenient container for an extensible set of attributes concerning group memberships. At this time, the only attributes specified as belonging to the the object class are "isMemberOf" and "hasMember."
URL for further info: http://middleware.internet2.edu/dir/docs/internet2-mace-dir-ldap-group-membership-200507.html
See also the OID Repository website reference for 1.3.6.1.4.1.5923.1.5.2.1