The pouches record the circumstances of capture and the eventual fate of merchant seamen captured during the war of 1939-1945. They were originally stored in card index drawers.
BT 373/1 - BT 373/359are indexed by ship name which was captured or lost due to enemy action. These contain miscellaneous papers relating to the circumstances of loss/ capture.
BT 373/360 toBT 373/3716 contain individual pouches of seamen respectively. Each pouch typically contains the following papers/ details: name of the ship lost usually written in red ink on the POW envelope; a card or form containing circumstantial details (including POW camp, POW number, Surname, Christian names, date of birth, place of birth, Discharge A number, rank or rating, name of ship, ships official number, date of loss of ship, next of kin, relationship, address and country of detention); Prisoner of War Branch PC 96 (postal censorship) forms vetting messages to and from family and friends; Envelope RS3 which usually has notes of release from captivity/ repatriation written on it where appropriate, containing many of the details from the POW card and additionally a National Service AF Account Number. Some of the pouches may also contain personal letters to and from prisoners of war.
Collective alphabetical listings of prisoners of war (as opposed to individual pouches) are contained in BT 373/3717 and BT 373/3720 - BT 373/3722. BT 373/3722 and BT 373/3721 include details and particulars of prisoners of war who died in captivity in Japan and Germany.