LDAP Links OpenLDAP Administration Guide contains very readable section "What is LDAP" LDAP RFCs RFC2251 Lightweight Directory Access Protocol (v3) Lightweight Directory Access Protocol (v3): Attribute Syntax Definitions Lightweight Directory Access Protocol (v3): UTF-8 String Representation of Distinguished Names The String Representation of LDAP Search Filters LDAP and Lotus Notes LDAP enabled on Notes... to change settings Replicating Notes data to OpenLDAP