Regulation 4 Size, colour and type of patrol sign
A patrol sign shall comprise a roundel and a pole on which the roundel is mounted.
The roundel shall be not less than 450 nor more than 470 millimetres in diameter and each of its faces shall be of the colour and type shown in the Schedule.
A protective strip, in these Regulations called a “perimeter strip”, may be applied to the perimeter of the roundel in accordance with the requirements of paragraph (4).
The requirements are that–
the perimeter strip shall not be retroreflecting;
the perimeter strip shall not be more than 15 millimetres wide;
the perimeter strip shall be either coloured red or uncoloured and transparent;
the part of the red border of the roundel not covered by the perimeter strip shall be at least 35 millimetres wide; and
the diameter of the part of the roundel coloured black and yellow shall be not less than 360 nor more than 370 millimetres.
A section of the pole at the bottom of the roundel may extend over the face of the roundel for the purpose of securing the roundel to the pole, but must not obscure any part of the black symbol.
Subject to paragraphs (7) and (8), the pole shall be coloured with alternating black and yellow bands not less than 280 nor more than 320 millimetres deep, beginning with a black band immediately below the roundel.
Any part of the pole which extends over the face of the roundel shall be coloured red or yellow in accordance with the colour of the part of the roundel covered by it.
If the pole is separable into two pieces when the patrol sign is not in use, the joint between the two pieces and not more than 5 millimetres of each piece of the pole on either side of the joint, may have an unpainted metallic finish.
Any fastenings used to attach the roundel to the pole must be–
coloured red or yellow in accordance with the colour of the part of the patrol sign on which they are placed; or
an unpainted metallic finish.
The pole shall not be separable into more than two pieces.
A black handgrip may be fitted to the pole within the black band immediately below the roundel.