The Traffic Signs Regulations and General Directions 2016 No. 362

SCHEDULE 2 Signs that warn of hazards and signs for bridges and other structures

PART 4 Traffic signs for bridges and other structures

3.  A number in column 4 of the sign table in this Part indicates that the plate or structure warning marking provided for at that item number in the sign table in Part 5 is an associated plate or marking of the sign provided for in the sign table in this Part at the item number at which the relevant column 4 entry appears.