Event Calendar

1918: "Potomac Code" was issued.

Sunday, June 24, 2018
Description: 24 June 1918: The "Potomac Code" - the first of the AEF "River" series of field codes was issued.

See the link below for "American Army Field Codes in the American Expeditionary Forces during the First World War." - an NSA declassified Friedman document.