CAB — Cabinet (UK)
CUL — Cambridge University Library
EGAF — Central Archive of the Russian Federation
FO — Foreign Office
GARF — State Archive of the Russian Federation
GATO — State Archive of the Province of Tyumen
HLRO — House of Lords Record Office
MI1c — Military Intelligence 1c (see SIS)
MI5 — Military Intelligence 5 – the Security Service
MI6 — Military Intelligence 6 (see SIS)
NYSC — New York Supreme Court
PRO — Public Record Offce (now TNA)
SIS — Secret Intelligence Service (MI1c now MI6)
TFGATO — Tobolsk Branch of the State Archive of the Province of Tyumen
TNA — The National Archive
WO — War Office