http://www.rfc-editor.org/rfc/rfc4533.txt
RFC 4533: The Lightweight Directory Access Protocol (LDAP) Content Synchronization Operation, K. Zeilenga, J.H. Choi2006-06-01T23:00:00-00:00This specification describes the Lightweight Directory Access Protocol (LDAP) Content Synchronization Operation. The operation allows a client to maintain a copy of a fragment of the Directory Information Tree (DIT). It supports both polling for changes and listening for changes. The operation is defined as an extension of the LDAP Search Operation. This memo defines an Experimental Protocol for the Internet community.