Nova-6

Confirmed by GamesTM magazine, codename Nova-6 is a Russian experimental weaponised chemical created by Russian Scientists that is reported to be important to the overall plot for Call of Duty: Black Ops. Furthermore, is it also reported that the main objective WMD is to find the chemical.

Trivia
Judging by the fact Nova-6 is contained in the name GKNOVA6, one can assume the two are directly related.