What is the meaning of dry toilet in wartime

The so-called dry latrine, also known as dry latrine, often seen in the city of human defense basement drawings, because the human defense basement is used in wartime to hide people or hide things in order to prepare for the war fire, so with the function of isolation from the outside world, so the septic tank can not be connected to the outside world, due to the fact that it is a closed place, so the human defense toilets are also known as (dry latrines) or (dry latrines), referring to the use of live water without the use of flushing temporarily with the toilet