The terms used by the RAF for offensive operations conducted by fighter, fighter-bomber and fighter-reconnaissance aircraft at low level evolved and changed over time. In 1941 and 1942 as the RAF fighters started 'leaning into Europe' a number of different names and titles were used initially by the different units and Groups within Fighter Command before the operational code names were standardised and defined. Early days you get terms such as "offensive strike' and 'offensive patrol' being used. Even into late 1942 when 11 and 12 Groups in Fighter Command had largely standardised on the likes of 'Ranger' and 'Rhubarb', 10 group was still on occasions using their own code names for the same types of operations.
Pre-D-Day the two main types of low level operations over occupied Europe were:
Ranger – armed reconnaissance, attacks against targets of opportunity and obtaining coverage of enemy transport movements and activity. Targets that could be attacked had to be clearly identifiable as targets that would minimise civilian casualties. Normally conducted by a pair of aircraft. There are instances where a 'Ranger' could involve two different aircraft types eg. a pair of Mosquito FB.IVs escorted by a section of four Mustang IIIs.
Rhubarb – armed reconnaissance, attacks against designated targets and obtaining coverage of enemy transport movements and activity. Normally conducted by a pair of aircraft although a section of two pairs could also be used.
In the immediate period leading up to D-Day and then through until VE-Day, the term
Armed Recce was added. It was essentially a low level patrol through a specified area, looking for targets of opportunity, strafing and/or bombing, but also noting enemy movements and locations/types of enemy traffic or similar for intelligence purposes. 'Armed Recces' were also used in the Netherlands looking for V-2 launch sites and V-2 support vehicles. Road, rail and canal barge traffic, as well as bridges, punts and ferries at river crossings were key items.
An 'Armed Recce' could be conducted by a pair, a flight of four, two flights, a squadron, in some instances the squadrons in a Wing might conduct armed recces in adjoining areas at the same time, thus able to provide support to the squadron in the adjoining area being covered if they encountered enemy fighters, or found more 'trade' on the ground in their area than they could handle and more resources were required - useful if the squadrons in the adjoining areas were not finding much 'trade' in their area.
Examples of descriptions of Armed Recces recorded in RAF Squadron Operational Record Books June 1944 - in this instance No.19 Squadron RAF flying Mustang IIIs, similar recorded in Spitfire, Typhoon, etc.
The RAF Fighter-Reconnaissance Squadrons, as their Mustang, Spitfire and Typhoon aircraft were armed, in addition to carrying their recce cameras, every operational sortie was considered to be an 'armed reconnaissance' as they were able to also shoot up targets of opportunity (when not explicitly ordered not to) and also obtain their visual and photographic reconnaissance for provision of intelligence - plus more immediate and effective evidence of the targets that they had attacked. Most of their sorties they basically referred to and recorded as Tac/R -Tactical Reconnaissance in those instances. Photo is example of recce photo obtained using the oblique mounted recce camera in a RAF Mustang IA/II by a pilot showing enemy supply vehicle strafed and burning after attack on a road in the Netherlands late 1944. In late 1942 and 1943, they also flew Rangers and Rhubarbs, where the primary purpose was not reconnaissance, but attacking targets beyond the range of the RAF's other primary fighter types of the time, making good use of the Allison engine Mustangs range and performance at low altitude. In that period a number of the RAF Army Co-operation Command/2TAF pilots racked up considerable scores of railway locomotives, railway rolling stock, vehicles, canal barges and the like destroyed or damaged.
