Definition: The word "S.T.S" is an abbreviation for the acronym "Soldier, Staff, Soldiers," which refers to the Soviet Union's version of the Army Corps of Engineers (ACE) in World War II. In World War II, the Soviet Union and Nazi Germany had a mutual understanding that all military units were considered part of the same entity. This meant that all military personnel on both sides could be considered "soldiers" as they would need to work together for the common good. The acronym "S.T.S," which stands for "Soldier, Staff, Soldiers," was a way of identifying soldiers who were assigned to various tasks, such as guarding bridges or buildings. These soldiers would serve in any one of three roles: staff members (the rank of engineer officer), soldiers (a higher rank than staff member), and S.T.S members. The word "S.T.S" has been used by the Soviet Union in its military operations for decades to refer to their own units and forces. The term can also be used metaphorically to describe a group or unit that is perceived as being responsible for the actions of others, such as "serving T.U.C.S." (together they form the S.T.S). Overall, the word "S.T.S" has become synonymous with the Soviet military's version of the Army Corps of Engineers during World War II.