"Svetleča površina signalne svetilke razen odsevnika" (1.5.11 do 1.5.19) pomeni pravokotno projekcijo svetilke na ravnino, ki leži pravokotno na njeno referenčno os in se dotika zunanje površine oddajanja svetlobe svetilke, pri čemer to projekcijo omejujejo robovi zaslonov na tej ravnini, od katerih vsak zmanjša svetilnost na 98 % celotne svetilnosti v smeri referenčne osi.
"Illuminating surface of a signalling lamp other than a reflex reflector" (1.5.11 to 1.5.19) means the orthogonal projection of the lamp in a plane perpendicular to its axis of reference and in contact with the exterior light-emitting surface of the lamp, this projection being bounded by the edges of screens situated in this plane, each allowing only 98 % of the total luminous intensity of the light to persist in the direction of the axis of reference.