The LDAP specification allows the use of attribute options. Attribute options can provide metadata about values for the attribute. Multiple options can be provided for a given attribute/value.

The classic example is language. displayName;lang-en tells you that this is the English version of displayName. displayName;lang-jp would be the Japanese version.

displayName;lang-en: Hideki Matsui
displayName;lang-jp: 松井秀喜

Generally, options behave intuitively. A query without specifying an option should match all relevant attributes (ie: displayName matches both displayName;lang-en and displayName;lang-jp), while a more specific query matches only relevant attributes (so displayName;lang-fr would not match either of the above examples).


  • Use Cases
  • Proposed Set of Options
  • Proposed eduperson Language
  • Draft RFC
  • Best Practices for Implementation
  • Results of Interop Testing of Existing Servers and Client Libraries


  • Notes from ACAMP 2012 session
  • RFC 3866: Language Tags and Ranges in the Lightweight Directory Access Protocol (LDAP)
  • RFC 4512: Lightweight Directory Access Protocol (LDAP): Directory Information Models (see §2.5)
  • RFC 4520 (BCP 64): Internet Assigned Numbers Authority (IANA) Considerations for the Lightweight Directory Access Protocol (LDAP)
    • As per §3.5, "All other options require Standards Action or Expert Review with Specification Required to be registered."
  • RFC 4522: Lightweight Directory Access Protocol (LDAP): The Binary Encoding Option
  • RFC 5646: Tags for Identifying Languages (Best Current Practice)
  • IANA Attribute Description Options Registry
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