Matching rules are also used in evaluating search filter elements, including distinguished names (DNs) and attributes. They are defined for each attribute based on the following properties:

  • EQUALITY: two attributes are equal based on case, exact match, and so forth
  • SUBSTR: assertion value is a substring of an attribute
  • ORDERING: greater than or equal, less than or equal, and so forth

server supports an APPROXIMATE matching rule that compares similar attributes based on fuzzy logic. Attributes that are similar or sound alike are matched. For example, petersen would match peterson.