M.A.S.K stands for Mobile Armored Strike Kommand - a special task-force led by Matt Trakker. Their enemies, led by Miles Mayhem, were called V.E.N.O.M. (Vicious Enemy Network Of Mayhem).
There have been two DC series - a four issue mini from 1985/1986 and an ongoing series (that lasted nine issues) in 1987.
In the UK, Mask had it's own title that lasted 80 issues (before merging with the Eagle from issue 345).