WWII A/C Squadron Markings

[tiger63]

I wanted a little info about how USAAF/USMC/USN designated their squadrons on their planes. I know there were tons of tail painting and such, but was there a basic way that all squadrons were required to use. I also wanted to know what the letters on the side of the P-51s meant.

[HawkerTempest5]

I'm not sure how it worked for the Navy and MC in the Pacific but in the ETO USAAF fighters such as the Mustang used the British system for aircraft and squadron ID. The letters on the side of a plane identify its squadron and the individual aircraft. For example the letters OU-V on the side of a plane would be as follows:
OU is the squadron code, in this case 485 (New Zealand) squadron. V is the individual aircraft letter. Sometimes a letter would be replaced by a number but the basic system remains the same. Hope that helps out a bit.

[Felix/FFDS]

Unlike the USAAF, the USN and USMC didn't go for much squadron identification once the war started.   Initially, and this was a pre-war carry over, Bombing 6 (Dauntless, CV-6 USS Enterprise) would have a 22-B-6 on the side of the plane, indicating plane No.22 of (B)ombing squadron 6 where the 6 refered to the carrier.

Later, as squadrons were rotated, and the large number of squadrons were created, this was changed.

Squadron markings, such as VF-17's skull and crossbones flag on its Corsairs, or other small squadron patch, could identify a particular squadron.

Later in the war, geometric designs on the tail marked a carrier wing (such as a white triangle marking the USS Enterprise)

Side note on the RAF... one squadron kept its squadron markings (blue-red-blue bars arrowhead) on its otherwise camouflaged aircraft into, I believe 1941 (Middle East)