I must admit I'd never heard of this but the first link explains it with the second link as the sharpe scheme
All about the SHARP Crash Helmet Safety Scheme
More or less everything you'll need to know about the SHARP crash helmet safety scheme for motorcycle crash helmets run by the UK Government.
billyscrashhelmets.co.uk
SHARP - THE HELMET SAFETY SCHEME
Welcome to SHARP, the Safety Helmet Assessment and Rating Programme, a scheme to help motorcyclists make an informed choice when buying a helmet.
sharp.dft.gov.uk