(1) Arabic numerals indicating the assigned floor number shall,
(a) be mounted permanently on each side of doors to exit stair shafts,
(b) be not less than 60 mm high, raised approximately 0.7 mm above the surface,
(c) be located 1 500 mm from the finished floor, and
(d) be contrasting in colour with the surface to which they are applied.
(2) Upper case letters indicating the designation assigned to each exit stair shaft shall be mounted permanently on each side of doors to the exit stair shaft and shall,
(a) be not less than 60 mm high, raised approximately 0.7 mm above the surface,
(b) be located 1 500 mm from the finished floor, and
(c) be contrasting in colour with the surface on which they are applied.