1. Information or a warning, requirement, restriction or prohibition specified in column 2 of an item in the sign table in Part 20 must be conveyed by a directional sign that includes a symbol provided for in column 3 on an appropriate background.
2. A symbol must be of the colour and type and comply with the requirements as to size, provided for in the diagram in column 3 or that diagram as varied in accordance with column 4.
3. The prohibition specified in column 2 at item 22 of the table must be conveyed by the inclusion of both the circular symbol and the symbol representing a plate and each must comply with paragraph 2.
4. The prohibition specified in column 2 at item 33 of the table must be conveyed by the inclusion of both circular symbols and each must comply with paragraph 2.
5. For the purpose of this Part and Part 20 an appropriate background is—
(a)that shown by either diagram A or diagram B at item 1 of the sign table in Part 2 where the sign is placed on an exit slip road or indicates the termination of a motorway;
(b)that shown by either diagram A or diagram B at item 2, 3, 4 or 5 of the sign table in Part 2;
(c)that shown by the diagram at item 2, 3 or 4 of the sign table in Part 9;
(d)that shown by the diagram at item 3, 5 or 6 of the sign table in Part 28.
6. If two or more symbols from the sign table in Part 20 are included in a sign and there is any difference in the size of the symbols as provided for in the relevant diagrams, the size of all the symbols used on the sign must be that of the largest.
7. The symbol at item 22 must not be included on a sign with any other symbol provided for in the sign table in Part 20.
8. The dimensions in the diagrams in the sign table in Part 20 are in stroke widths.
9. A symbol provided for in Part 20 may be varied when used on a directional sign by the addition of a white border around the symbol to ensure adequate contrast between the symbol and the background of the sign.
10. A symbol provided for at item 20, 22, 23, 24 or 39 to 46 of the sign table in Part 20 may be used only on a sign which incorporates a route symbol shown by a diagram in the sign table in Part 7.