A rear naked choke, for example, communicates that the choker wants the chokee to go to sleep. Like, right now.

Pvt. Abdulla Rasheed, quick reaction force I, National Security Service, Republic of Maldives, executes a rear choke on his partner during close combat training. The training involved techniques throughout the tan, gray, and green belt courses.
The Marine Corps Martial Arts Program is growing in popularity and because of its combat efficient techniques, the MCMAP Far East School has been sending instructors to foreign countries to train allies for close combat. MCMAP instructors recently travelled to Maldives to train members of the military there.

Photo by Cpl. Benjamin M. George