Any sort of Coy markings haven't been used for many years, not officially anyway. The only real exception to this is Sqn triangle, square, circle which goes around the callsign, also some tank Sqn's still name their tanks with a name starting with the letter of that Sqn ie A, B, C, D. As Bazz say's with Union flag sticker.
There are other exceptions obviously like Opfor but these are not permenant markings.