Here perhaps are some indicators, providing a degree of context.
From, War Diary, 1st Bn The Black Watch (Nov-Dec 1942)
c 24.11.42 (SIDI SULEIMAN) Cardigan, shorts, steel helmets, battle order. Tps will remain properly dressed throughout the move,
i.e. Helmets will NOT BE REMOVED
[No Date] 1942 Raid ADM.- DRESS A Coy will wear battle-dress trews, patrol boots, cardigans and NO head-dress
1.12.42 Greatcoats will be worn but can be taken off on orders of Coy Commanders. BD Blouses will be worn. Steel helmets NOT be removed.
26.12.42 Steel helmets, greatcoats. (to be removed on orders of [Sp cmds] Equipment will not be worn but made up to wear over cardigans.