The DVLA at Swansea has sent out new instructions to all UK licence
holders:


"In order to assist other motorists in identifying potentially dangerous
drivers, it is now compulsory for anyone with a lower than average driving
ability to display a warning flag.

The flag, comprising of a red cross on a white background should be
attached in a prominent position to the top of at least one door of the
vehicle.

For drivers of exceptionally low ability, additional flags must be
displayed."