Options are short, case-insensitive text strings that differentiate between attribute descriptions. For example, the LDAPv3 specification defines only one type of option, the tagging option, that can be used to tag language options, such as cn;lang-de;lang-sp or binary data, such as userCertificate;binary. You can also extend the schema by adding your own attribute definitions.

Attributes have the following properties:

  • Attributes can be user attributes that hold information for client applications, or operational attributes used for administrative or server-related purposes.

    To specify the purpose of the attribute, use the USAGE element.

  • Attributes are multi-valued by default. Multi-valued means that attributes can contain more than one value within an entry.

    If the attribute should contain at most one value within an entry, include the SINGLE-VALUE element.

  • Attributes can inherit properties from a parent attribute as long as they both have the same USAGE, and the child attribute has the same SYNTAX, or its SYNTAX allows values that are a subset of the values allowed by the SYNTAX of the parent attribute. For example, the surname (sn) attribute is a child of the name attribute.