Field’ meant 25-pdr (and 18/25-pdr, 18-pdr carriage with 75-mm, 18-pdr gun and 4.5-inch howitzer early in the war and a few self-propelled (SP)105-mm later. 'Army Field Regiments’ were field regiments that were not under divisional command. 'Jungle Field Regiments' in Burma had a mix of guns and mortars. ‘Mountain’, 'Pack' and ‘Light’ meant 3.7-inch or 75-mm howitzer, or mortars in a few cases. The howitzers were usually jeep towed but some were on animal transport. ‘Airlanding’ meant 75-mm (initially 3.7-inch howitzer). ‘Medium’ meant 5.5 or 4.5-inch gun (and 6-inch howitzer and 60-pdr gun initially, with the latter re-introduced in Burma in 1944). The shortage of medium artillery in 1941-2 led UK and Australia to acquire some US built French WW1 155-mm M1917/18 howitzers. ‘Heavy’ meant 7.2-inch howitzer and 155-mm gun (and 6-inch gun, 8 and 9.2-inch howitzer early in the war), although at the beginning of the war most coast artillery units were also called 'heavy' . ‘Super Heavy’ meant 8-inch gun, 240-mm howitzer, 9.2-inch railway gun and 12-inch howitzer. ‘Survey’ regiments contained survey, sound ranging and flash spotting elements. found the info here: Royal Artillery Methods in World War 2 BL 4.5 inch Medium Field Gun - Wikipedia, the free encyclopedia BL 5.5 inch Medium Gun - Wikipedia, the free encyclopedia BL 7.2 inch Howitzer Mk.I - Wikipedia, the free encyclopedia BL 60 pounder gun - Wikipedia, the free encyclopedia
