The Free On-line Dictionary of Computing (30 December 2018):

Lightweight Directory Access Protocol
LDAP

    (LDAP) A protocol for accessing on-line
   directory services.

   LDAP was defined by the IETF in order to encourage adoption
   of X.500 directories.  The Directory Access Protocol (DAP)
   was seen as too complex for simple internet clients to use.
   LDAP defines a relatively simple protocol for updating and
   searching directories running over TCP/IP.

   LDAP is gaining support from vendors such as Netscape,
   Novell, Sun, HP, IBM/Lotus, SGI, AT&T, and
   Banyan

   An LDAP directory entry is a collection of attributes with a
   name, called a distinguished name (DN).  The DN refers to the
   entry unambiguously.  Each of the entry's attributes has a
   type and one or more values.  The types are typically
   mnemonic strings, like "cn" for common name, or "mail" for
   e-mail address.  The values depend on the type.  For
   example, a mail attribute might contain the value
   "donald.duck@disney.com".  A jpegPhoto attribute would contain
   a photograph in binary JPEG/JFIF format.

   LDAP directory entries are arranged in a hierarchical
   structure that reflects political, geographic, and/or
   organisational boundaries.  Entries representing countries
   appear at the top of the tree.  Below them are entries
   representing states or national organisations.  Below them
   might be entries representing people, organisational units,
   printers, documents, or just about anything else.

   RFC 1777, RFC 1778, RFC 1959, RFC 1960, RFC 1823.

   LDAP v3
   (http://kingsmountain.com/LDAPRoadmap/CurrentState.html).

   [Difference v1, v2, v3?]

   (2003-09-27)