6.—(1) A reference in these Regulations to the inclusion on a sign of a “time period” means the inclusion of a period of time that complies with the requirements of Part 1 of Schedule 18.
(2) More than one period of time may be included in a sign if appropriate for conveying the meaning of the sign.
(3) A reference in these Regulations to the inclusion on a sign of a “permitted parking expression” means the inclusion of an expression that complies with the requirements of Part 2 of Schedule 18.
(4) An expression of distance on a sign must be in imperial units and comply with the requirements of Part 3 of Schedule 18.
(5) The provisions of this regulation do not apply where more specific provision in relation to a particular sign is made elsewhere in these Regulations.