The following is from findmypast.
"We've just added over 4 million new records making our collection of British Army Service records the largest available online.
Start exploring these new records, also known as the 'burnt records' after being damaged or destroyed in a World War 2 bombing raid. These records include multiple images per person and contain fascinating details such as a list of the personal effects of men who died at the front.
Whilst scanning these records we have found over half a million men whose details were buried deep within other records, so you won't have found them before.