These records detail the sea service record of merchant seamen engaged in the liberation of Europe (6 June 1944 to 8 May 1945). They give the seaman's name, discharge 'A' number, rank or rating and qualifications together with details of the ships on which they served.
The catalogue entry for each seaman's pouch within BT 391 includes: surname or patronym, forename(s) or initials, discharge 'A' number with prefix code where appropriate, date of birth and sometimes place of birth. The place of birth information, (where it exists), is as it was endorsed but place names have not been verified.
A discharge 'A' book and the related registered discharge 'A' number are issued to a seaman on joining the service. During their service seamen carried their discharge books from ship to ship as proof of their character and as a guide to employers as to their experience and rating.
The registered number has a regularised format that normally includes a prefix letter, referring to the nationality of the seaman. The seaman retains this number throughout his or her service even when the discharge 'A' book is lost or destroyed. In common parlance the book is referred to as the discharge book or papers. The prefix letters used are as follows:
- Numbers (no prefix) = Various nationalities (mainly British)
- A = India and Pakistan BAR = Barbados
- BG = British Guyana
- B/HT = British - born in India
- C/O = Bangladesh citizens
- C or CAN = Canadian
- E = Eire
- F = Falkland Islands
- G = Ghana
- HK or Hong Kong = Hong Kong
- I, Ind or India = Indian nationality
- J or Jam = Jamaica
- K = Tanganyika
- K/O = India or Pakistan
- M or Malta = Malta
- Mau = Mauritius
- Nig = Nigeria
- R = British seamen
- S = Various (mainly British)
- SA = South Africa
- SE = Western Isles and Northern Ireland
- SEY = Seychelles
- SI = Singapore
- SL = Sierra Leone
- St L = St. Lucia
- T & T = Trinidad and Tobago
- Z or Zan = Zanzibar
The file reference of COMNO stands for Combined Office Merchant Navy Operations.
In some cases, there are two pouches relating to the same seaman.
Some pouches are empty but include details of service on the reverse.