A black operation or black op is a covert or clandestine operation by a government agency, a military unit or a paramilitary organization; it can include activities by private companies or groups. Key features of a black operation are that it is secret and it is not attributable to the organization carrying it out.

Most of the Western Front locations presented in the first two Call of Duty games and the more recent Call of Duty: WWII are quite accurate, especially France. The names of the towns, villages, and even the operations are well-researched (as they should be) and even recreated with decent attention to detail.