A DZ Flash is a badge or patch worn by the Airborne forces of the British Army and all squadrons of the RAF Regiment. DZ stands for 'drop zone'. In RAF Regiment use, these flashes distinguish between squadrons, although within the RAF Regiment only II Squadron has a parachute capability.
^"AP 1358, CHAP 7"(PDF). 0733. RAF Regiment. Members of the RAF Regiment wear distinguished arm badges and shoulder slides as follows: a. RAF Regiment Shoulder Badge. b. Shoulder/Chest Epaulette Rank Slides c. Sqn Drop Zone (DZ) Patches. Sqn DZ patches may be worn on the CS 95 jacket with the sqn cdrs permission. They are to be OG with the centrepiece of the authorised Sqn badge embroidered in black, coloured versions are not to be worn. They are worn centrally mid-way up the right sleeve of the field jacket (or parachute smock if appropriate), positioned below parachutist wings if awarded. RAF Regt personnel not serving on sqns may wear the RAF Regt DZ patch with embroidered crossed rifles and astral crown instead.