S. O. S. Service of Supplies. Referred to men engaged in getting
supplies of food and ammunition to the troops.
A. P. O. Army Post Office. The post offices were known by numbers so
that names of towns giving location of troops would not be placed on
paper.
A. E. F. American Expeditionary Force or Forces. Both terms were used,
and referred to troops, welfare workers, etc., serving overseas.
G. O. General Orders. Orders issued from general army headquarters.
Det. Detached.