What does acl-bind exactly

Hello,

what does acl-bind exactly in ldap backend (slapd-ldap)? I don't understand the explenataion in available documentations.

The manpage says "... that is internally used by the proxy to collect info related to access control ...", but which informations are needed from the remote server?

Further the manpage says "The identity (...) is supposed to have read access on the target server to attributes used on the proxy for ACL checking ...", but which attributes are mean?

Kind regards,

Markus Martinet