Would anyone know the meaning of "Usted" when talking about Army Commands in the UK? This was used in communications alongside "Soutco" (Southern Command), "Norco" (Northern Command), "Eastco" (Eastern Command), "Westco" (Western Command), "Scotco" (Scottish Command), "Seco" (South Eastern Command), and "BTNI" (British Troops in Northern Ireland). As such, I assume that "Usted" is probably either London District or Anti-Aircraft Command, although I have seen "AACo" for the latter. Any help appreciated!
