h3.Definition: Attribute Type
An attribute type is a [schema|Definition -- Schema] element that correlates an [OID|Definition -- Object Identifier] and a set of names with an [attribute syntax|Definition -- Attribute Syntax] and a set of [matching rules|Definition -- Matching Rule].
The components of an attribute type definition include:
* An OID used to uniquely identify the attribute type.
* A set of zero or more names that can be used to more easily reference the attribute type.
* An optional equality matching rule that specifies how equality matching should be performed on values of that attribute. If no equality matching rule is specified, then the default equality rule for the associated attribute syntax will be used. If the associated syntax doesn't have a default equality matching rule, then equality operations will not be allowed for that attribute.
* An optional ordering matching rule that specifies how ordering operations should be performed on values of that attribute. If no ordering matching rule is specified, then the default ordering rule for the associated attribute syntax will be used. If the associated syntax doesn't have a default ordering matching rule, then ordering operations will not be allowed for that attribute.
* An optional substring matching rule that specifies how substring matching should be performed on values of that attribute. If no substring matching rule is specified, then the default substring rule for the associated attribute syntax will be used. If the associated syntax doesn't have a default substring matching rule, then subsring operations will not be allowed for that attribute.
* An optional syntax OID that specifies the syntax for values of the attribute. If no syntax is specified, then it will default to the directory string syntax.
* A flag that indicates whether the attributes of that type will only be allowed to have a single value in any entry in which they appear.
* An optional [attribute usage|Definition -- Attribute Usage] string indicating the context in which the attribute may be used.
* An optional flag that indicates whether the attribute can be modified by external clients.
The set of attribute types defined in the server may be determined by retrieving the {{attributeTypes}} attribute of the [subschema subentry|Definition -- Subschema Subentry]. For more information about attribute types, see the [Understanding Attribute Types] document.
An attribute type is a [schema|Definition -- Schema] element that correlates an [OID|Definition -- Object Identifier] and a set of names with an [attribute syntax|Definition -- Attribute Syntax] and a set of [matching rules|Definition -- Matching Rule].
The components of an attribute type definition include:
* An OID used to uniquely identify the attribute type.
* A set of zero or more names that can be used to more easily reference the attribute type.
* An optional equality matching rule that specifies how equality matching should be performed on values of that attribute. If no equality matching rule is specified, then the default equality rule for the associated attribute syntax will be used. If the associated syntax doesn't have a default equality matching rule, then equality operations will not be allowed for that attribute.
* An optional ordering matching rule that specifies how ordering operations should be performed on values of that attribute. If no ordering matching rule is specified, then the default ordering rule for the associated attribute syntax will be used. If the associated syntax doesn't have a default ordering matching rule, then ordering operations will not be allowed for that attribute.
* An optional substring matching rule that specifies how substring matching should be performed on values of that attribute. If no substring matching rule is specified, then the default substring rule for the associated attribute syntax will be used. If the associated syntax doesn't have a default substring matching rule, then subsring operations will not be allowed for that attribute.
* An optional syntax OID that specifies the syntax for values of the attribute. If no syntax is specified, then it will default to the directory string syntax.
* A flag that indicates whether the attributes of that type will only be allowed to have a single value in any entry in which they appear.
* An optional [attribute usage|Definition -- Attribute Usage] string indicating the context in which the attribute may be used.
* An optional flag that indicates whether the attribute can be modified by external clients.
The set of attribute types defined in the server may be determined by retrieving the {{attributeTypes}} attribute of the [subschema subentry|Definition -- Subschema Subentry]. For more information about attribute types, see the [Understanding Attribute Types] document.