Originally posted by Fidd
Hmmm Osprey books show other aircraft carrying pennants on starboard side as well, but as they don't show both sides of the same aircraft I can't tell!
Hmm... the only explanation is that it's applied to the side you access the aircraft. BTW, is this a Sqn Ldr pennant that Osprey show being on the starboard side? I think the Sqn Ldr pennant can be applied either side but the port is the norm.
I know that Typhoon's only have it on the port side, like the Typhoon in AH with Wg Cdr pennant. I think Spitfires and Hurricanes are on the port side too. (AH Spit14 has Wg Cdr pennant on port side too).
Here's the BBMF Spitfire displaying the Wg Cdr pennant on the port side:

and not visible on starboard side

I'll dig through my books and see if there is a clearer definition of which side it's normally applied.