During WW II the troops had to be fed and this is where the NAAFI came to the fore. They ran the canteens that fed the troops.
NAAFI stands for Navy, Army, Air Force Institute.

Like members of the armed forces the staff also wore a uniform. This is my mother around 1940/41.
She was employed by the NAAFI at their site in Heaton Park, Manchester.
Not only were there British troops here but also members of the Free French Army and a considerable number of Poles who trained for the Parachute Regiment at Ringway Airport, Manchester.
.