Linked values are defined in the Active Directory (AD) schema by the respective attributeSchema class object’s linkID property. The forward link is defined with an even number (n) in the linkID, whereas the matching back-link attribute has an odd number (n+1) as the linkID. In my user/group example, the group’s member attribute has a linkID of 2 and the memberOf attribute has a linkID of 3. You can use an LDAP editor such as ldp.exe to determine all linked values in the AD schema and search for any schema objects that contain values in the linkID attribute, as Figure A shows. Figure B shows the output of such a search.