Reference document

ACP 133(D)
Common Directory Services and Procedures


The function of this document, Allied Communication Publication (ACP) 133, is to define the Directory services, architecture(s), protocols, schema, policies, and procedures to support Allied communications, including Military Message Handling System (MMHS) services based on ACP 123, in both the strategic and tactical environments. The Directory services are based on the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) X.500 Series of Recommendations and the International Organization for Standardization (ISO) / International Electrotechnical Commission (IEC) 9594. These Directory specifications will be referred to as X.500 in this document. Note that familiarity with X.500 is assumed. The Allied Directory Services defined in this document are based on the X.500 Directory recommendations (exact documents and version numbers listed in References on page REF-1). It is expected that an evolutionary period will be necessary for existing Directory Services to become ACP 133-compliant. In this sense, ACP 133 is viewed as a “target”. The manner, means, and duration of such evolution are outside the scope of ACP 133.

This ACP applies to communication among the Allied Directory domains and within a domain for combined operations. It defines a common Directory schema which shall be supported by all Allies for international and combined operations. It offers support for Internet mail users and transitional support for ACP 127/Joint Army, Navy, Air Force Procedure (JANAP) 128. The Directory has the potential to support different views of directory information such as white pages and yellow pages services.

Local interfaces and requirements, such as the specifics of terminal display and local caching, are part of this publication where required to ensure interoperability. ACP 133 includes requirements for which directory information must be displayed to the user, but the format of the display is outside the scope of this document.

The forth version of ACP 133 defines the services, schema, and protocols required of X.500 Directory System Agents (DSAs) and Directory User Agents (DUAs) to support electronic mail (e-mail), S/MIME, Message Handling System (MHS), MMHS, ACP 127 interworking and traditional communications. It also identifies security mechanisms that meet the security requirements for strong authentication, confidentiality, integrity, availability, and privilege/label management. As national systems and products mature, this document will be expanded to include more procedural guidance for managing the directory, support for other applications, and additional guidance for operation of tactical, mobile and deployed directories.

Responsible Party

DPC NATO Allied Communications Publications CaT




Flag Date RFC Version
added 2010-11-16 4-39 5
changed 2011-10-16 5-63 6
changed 2019-10-11 12-014d 13
changed 2020-01-24 12-034 13


This standard is used by the following service profiles: