(1) A traffic-related item complies substantially with these Rules if—
(a) it is a reasonable likeness of a diagram in Schedule 4 of that kind of traffic-related item; or
(b) for a traffic-related item of a kind for which there is not a diagram in Schedule 4—it complies substantially with a description of that kind of traffic-related item in the Rules and, if the description includes a symbol for which there is a diagram in Schedule 4, the symbol on the item is a reasonable likeness of the diagram.
(2) A traffic-related item may be a reasonable likeness of a diagram of a kind of traffic-related item mentioned in these Rules even though—
(a) the dimensions of the item, or of anything on the item, are different; or
(b) the item has additional information.
(3) A symbol on a traffic-related item may be a reasonable likeness of a diagram of a kind of symbol mentioned in these Rules even though the dimensions of the symbol, or of anything on the symbol, are different.