Zoran. This is a puzzle; it says 243 Sqn. ( the Spitfire in the background has their codes "SN") and the date would be July 43; but which letter is their temporary code, X or Y, and "E" was added for some reason. "X" was already allocated so I presume it's "Y" ?
Nick
https://www.asisbiz.com/il2/Spitfire...M-CNA1029.html