бэкэнд метакаталога для slapd  (metadirectory backend to slapd)
  
LDAP Proxy resolution (a possible evolution of slapd-ldap(5)):
In case the rewritten DN is an LDAP URI, the operation is
       initiated towards the host[:port] indicated in the uri, if it
       does not refer to the local server.  E.g.:
         rewriteRule '^cn=root,.*' '%0'                     'G{3}'
         rewriteRule '^cn=[a-l].*' 'ldap://ldap1.my.org/%0' ':@'
         rewriteRule '^cn=[m-z].*' 'ldap://ldap2.my.org/%0' ':@'
         rewriteRule '.*'          'ldap://ldap3.my.org/%0' ':@'
       (Rule 1 is simply there to illustrate the `G{n}' action; it could
       have been written:
         rewriteRule '^cn=root,.*' 'ldap://ldap3.my.org/%0' ':@'
       with the advantage of saving one rewrite pass ...)