# The Traffic Signs Regulations and General Directions 2016, Paragraph 18

Extent: E+W+S

(1) The white area is to be filled with maps or a legend in any colour with lettering of any colour.
(2) The x-height of a legend referred to in sub-paragraph (1) must not exceed 25 mm.
(3) The “i” symbol may be omitted.
(4) The sign may have more than one panel or side if each is of the design prescribed in the diagram.

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Source: https://www.legislation.gov.uk/uksi/2016/362/schedule/11/paragraph/18 (the official version)
Page: https://openlegislation.uk/traffic-signs-regulations-and-general-directions-2016/schedule-11/paragraph-18
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.