The answer is OC hope helps
A mutation that happens only on one point of the gene
The army developed the military occupational specialty system for tracking the weaponry skills in WWII.
These MOS system had various fields like communications department, gunnery and gunnery control department, field and coast artillery, air crew, security departments etc.
The selected soldiers are assigned their specific tasks and all the groups are organised by a alphanumeric code system.
It was around the civil war time in the south when white people and black people were separated... also called segregation