This SAE Aerospace Recommended Practice (ARP) recommends criteria for the design and installation of Head-Up Display (HUD) systems. The recommendations are applicable to HUD systems for transport category aircraft, which display flight information (focused at infinity) in the forward field of view. The HUD total system requirement recommendations shall primarily lead to certifiable fail-passive CAT III characteristics and performance. This document forms a part of these recommendations. This document does not address devices for peripheral vision of displays worn by the pilot, nor the presentation of Enhanced Vision System (EVS) information.