 Chinese Travel Document is a blue-covered passport-sized booklet clearly denoted "TRAVEL DOCUMENT" as opposed to the usual red-covered passport.Historically, laissez-passers were commonly issued during wartime and at other periods, literally acting as a pass to allow travel to specific areas, or out of war zones or countries for various officials, diplomatic agents, other representatives or citizens of third countries.In these contexts, a laissez-passer would frequently include quite specific and limited freedom of movement.