56. (1) Within the United Kingdom any signal or marking which is specified in this Section and which is given or displayed—
(a)by any person in an aircraft; or
(b)at an aerodrome; or
(c)at any other place which is being used by aircraft for landing or take-off,
shall have the meaning assigned to it in this Section.
(2) Apart from those referred to in rule 60(6) and the distances at which markings must be placed, all dimensions of signals or markings specified in this Section of these Rules shall be subject to a tolerance of 10 per cent, plus or minus.