Revision Standard - Inactive-Withdrawn. This standard represents a revision of material contained in the previous edition of IEEE Std 172-1971. The committee reviewed all of the terms, selected those which it considered appropriate, and deleted others. In preparation for this revision, the committee has included additional definitions relating to marine navigation, updated navigation equipment definitions, and included navigation terms where appropriate for completeness. This revision additionally encompasses suggestions and recommendations from a number of IEEE committees and panels who have contributed to this standard.