I would like one question,why is not included in this part of the E4 Messer?

[Osprey]

Originally Posted by 41Sqn_Banks

The don't give so much about the names anyway. Just look at the Spitfire names, the "a" in "Mk. Ia" was added to all machine gun armed "Mk. I" when the canon armed "Mk. Ib" came in service. So having a "Mk. I" and a "Mk. Ia" doesn't make much sense as they are the same subversion.

I suspect it's been said already but that's not true. The Spitfire letter denotes the wing type, A being 8 gun, B supporting cannon, C a multipurpose wing of cannon or mixed 303 and E 50cal + cannon