Rookie --"Seriously, I still don't get the Mk(insert Roman Numeral here) thing, but if it works for you all, so be it. It just makes one seem detached from the rest (In my opinion) and know it would not work for our squad."--
Ain't no big thing; started back in '95 or so. Our CO wanted to bring in some fresh blood (yours truly included), but didn't want to drop the original founders, so he started Damned MkI as a frequent flyers squad, (sorta like the Spitfires, I guess) with The Damned as a more honorary group. Then one of our go-getters decided to start up a dedicated buff squad -- MkII. Then a MacAW Squadron -- MkIV. And a Warbirds Squadron -- MkV. Etc. etc.
We thought it sounded less pretentious then, say [[ahem]], the Damned 'Skull' Squadron or the Damned 'Blood' Squadron

How many old time squadrons still around? I miss the DiKtAtOrS
Isn't DFA still around?