Internal List of Correspondences

Directory Server identifies matching rules by OID. The server keeps an internal list of which matching rule plug-ins handle which OIDs.

Directory Server uses the internal list to determine which plug-in to call when the server receives an extensible match filter search request that includes a matching rule OID. Directory Server initially builds the list as matching rule plug-ins register OIDs that the plug-ins handle using slapi_matchingrule_register() in the plug-in initialization function.