This standard establishes the requirements for the file format component of the National Imagery Transmission Format Standard (NITFS). The file format described in this document is called the NITF. The NITFS is a collection of related standards and specifications developed to provide a foundation for interoperability in the dissemination of imagery and imagery associated data among different computer systems.

Purpose. This document, NITF 2.1, provides a detailed description of the standard file format structure. It specifies the valid data content and format for all fields defined within an NITF file. For this document, NITF refers to NITF Version 2.1. Several NITF implementation issues are addressed in the appendices. An example of NITF as the basis for file formation in tactical communications is provided in Appendix E. Certifiable implementation of the NITF for support of interoperability is subject to constraints not specified in this standard. Pertinent compliance requirements are defined in DoDI 8330.01.

Applicability. This standard is applicable to Department of Defense (DOD) and Intelligence Community (IC) members. It is mandatory for all Secondary Imagery Dissemination Systems (SIDS) in accordance with the Assistant Secretary of Defense for Command, Control, Communications, and Intelligence (ASD/C3I)) memorandum, Subject: National Imagery Transmission Format Standard (NITFS), 12 August 1991, and is applicable also to all types of primary imagery systems such as Unmanned Aerial Systems (UAS), archives, and libraries. New equipment and systems, those undergoing major modification, or those capable of rehabilitation, will conform to this standard.