1. A rear marking of a type shown in one of the above diagrams shall have the dimensions shown in relation to that diagram.
2. Any variation in a dimension (other than as to the height of a letter) specified in any of the above diagrams shall be treated as permitted for the purposes of this Schedule if the variation—
(a)in the case of a dimension so specified as 250 mm or as over 250 mm does not exceed 2.5 per cent. of that dimension;
(b)in the case of a dimension so specified as 40 mm or as over 40 mm but as under 250 mm does not exceed 5 per cent. of that dimension; or
(c)in the case of a dimension so specified as under 40 mm does not exceed 10 per cent. of that dimension.
3. Any variation in a dimension as to the height of a letter specified in any of those diagrams shall be treated as permitted for the purposes of this Schedule if the variation —
(a)in the case of a dimension so specified as 105 mm does not exceed 2.5 per cent. of that dimension; or
(b)in the case of a dimension so specified as 70 mm does not exceed 5 per cent. of that dimension.
4. Any variation in a dimension as to the angle of hatching specified in any of those diagrams shall be treated as permitted for the purposes of the Schedule if the variation does not exceed 5 degrees.
5. A rear marking of a type shown in diagrams 1 or 4 above shall be constructed in the form of a single plate, and every rear marking shown in diagrams 2, 3 or 5 above shall be constructed in the form of two plates of equal size and shape.
6. The height of each half of the marking shown in diagram 3 above may be reduced to a minimum of 140 mm provided the width is increased so that each half of the marking has a minimum area of 980 cm2.
7. All letters incorporated in a rear marking of a type shown in diagrams 4 or 5 above shall have the proportions and form of letters as shown in Schedule 25.