Where explosives allocated on classification the UN Number 0018, 0019, 0020, 0021, 0076, 0077, 0143, 0224 or 0301 are carried in a vehicle or container, there shall be displayed, in accordance with paragraph 1, subsidiary hazard signs which—
(a)
are in the form of the following diagram; and
(b)
comply with the measurements in the diagram except that larger measurements may be used in which case the measurements shall be increased proportionally.
