EX?

[Starhammer]

What does EX behind a scenario mean?

[-Greg-]

I guess it's Extra.

BB are the 16 scenarios in the base game.
PT,EF,MT are from the Pacific Theater, Eastern Front & Mediterranean Theater expansions.
TP are from the Terrain Pack expansion though it seems to be missing scenario 1422 - Schwammenauel Dam.

EX are official scenarios from the Days of Wonder website. There are 100s more official scenarios so maybe they'll add more Ex's.

Rzhev, The Meat Grinder isn't in the official scenarios section so not sure why it's there. I think it's from the Scenarios from the Front list which are made by fans using the editor.

[Cavetoad]

I was wondering too, thanks for asking and answering!