LDAPv3 enables you to build match operators and rules for a particular attribute. Matching rules define how to compare attribute values with a particular syntax. In other words, a matching rule defines how potentially matching attributes are compared. For example, a matching rule can define whether or not to take text case into account when comparing attributes.
When the rules are created, they can be referred to in a search filter.
For example, the following search filter compares entries containing the surname “Jensen” by using the matching rule designated by OID 18.104.22.168:
The following example illustrates the use of the ":dn" notation to indicate that OID 22.214.171.124 should be used when making comparisons, and that the attributes of an entry\qs distinguished name should be considered part of the entry when evaluating the match: