Glossary of terms and abbreviations

Name: G2
Explanation: Officer in the staff branch of military headquarters. G2 Branch was responsible for security and intelligence.
Name: GCO

Group Commander. A GCO was in command of a group of Auxiliary Units operational patrols. 

Name: GHQ

General Headquarters. GHQ Auxiliary Units was based at Coleshill House, Wiltshire, from July 1940 to January 1945. 

Name: GHQ Line

General Headquarters Line. A defence line built in the UK during WW2 to contain an expected German invasion.

Name: GPO

General Post Office