We had a problem with Domino LDAP at a customer site:
A group of pilot users of different domains should be made accessible via a test Domino LDAP server. So we copied the person documents from the Domino directories of the other domains into the Domino directory of the test LDAP server. Unfortunately all of these users were not visible in the LDAP directoy afterwards.
The solution was to copy all necessary certifier documents from the other Domino directories into the Domino directory of the LDAP server. As soon as the certifiers documents existed all users suddenly showed up via LDAP.
Domino LDAP and Certifiers