1. Introduction

The Lightweight Directory Access Protocol (LDAP) [RFC4510] defines a network representation of a search filter transmitted to an LDAP server. Some applications may find it useful to have a common way of representing these search filters in a human-readable form; LDAP URLs [RFC4516] are an example of one such application. This document defines a human-readable string format for representing the full range of possible LDAP version 3 search filters, including extended match filters.

This document is a integral part of the LDAP technical specification [RFC4510], which obsoletes the previously defined LDAP technical specification, RFC 3377, in its entirety.

This document replaces RFC 2254. Changes to RFC 2254 are summarized in Appendix A.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119].