The contemporary term false flag describes covert operations that are designed to deceive in such a way that the operations appear as though they are being carried out by entities, groups, or nations other than those who actually planned and executed them. Historically, the term "false flag" has its origins in naval warfare where the use of a flag other than the belligerent's true battle flag before (but not while) engaging the enemy has long been accepted as a permissible ruse de guerre; by contrast, flying a false flag while engaging the enemy constitutes perfidy. Operations carried out during peace-time by civilian organizations, as well as covert government agencies, can (by extension) also be called false flag operations if they seek to hide the real organization behind an operation.