# The Motor Vehicles (Designation of Approval Marks) Regulations 1979, Paragraph 10

Extent: E+W+S+N.I.

(1) In the markings relating to items 23, 23A and 23B in Schedule 4 there shall be added above the rectangle:—
(a) the letter “A” in the case of a three-point belt,
(b) the letter “B” in the case of a lap belt, and
(c) the letter “S” in the case of a safety belt which is neither a three-point belt nor a lap belt.
(2) The letters referred to in sub-paragraph (1) above shall be preceded by the letter “Z” when the safety belt is part of a restraint system.
(3) The letters referred to in sub-paragraph (1) above shall be supplemented by:—
(a) in the case of a safety belt fitted with an energy absorber, the letter “e”; ...
(b) in the case of a safety belt fitted with a retractor, the letter “r” followed by:—
(i) the figure “1” if the retractor is a non-locking retractor, or
(ii) the figure “2” if the retractor is a manually unlocking retractor, or
(iii) the figure “3” if the retractor is an automatically locking retractor, or
(iv) the figure “4” if the retractor is an emergency locking retractor, or
(v) the figure and letter “4N” if the retractor is an emergency locking retractor with higher response threshold,
followed by the letter “m” if the retractor is an emergency locking retractor with multiple sensitivity; and
(c) in the case of a safety belt with a pre-loading device, the letter “p”.
(4) In the case of a marking prescribed at either item 23A or item 23B in Schedule 4, the marking shall bear a symbol consisting of a rectangle with a motor vehicle of category M1 crossed out, if the safety belt is fitted with a retractor which, in normal driving conditions, does not restrict the freedom of movement of the wearer of the safety belt, but has special properties as regards use in vehicles of categories M2, M3, N1, N2 and N3.

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Source: https://www.legislation.gov.uk/uksi/1979/1088/schedule/5/paragraph/10 (the official version)
Page: https://openlegislation.uk/motor-vehicles-designation-of-approval-marks-regulations-1979/schedule-5/paragraph-10
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.