Individual papers were identified in the card index by a country code, a paper number and a file number. These have to be translated to modern PRO references. Each country had its own code, composed of a unique stem number, to which could be added extra numbers or letters. Prisoners News Coal and tonnage Series FO 382 FO 371 FO 383 FO 395 FO 382 P or Pr with an abbreviated country name denotes the Prize series in FO 372, the Treaty series. When file and paper number are the same, the whole file is relevant.
Some subjects have cross-references on the first card entry.
The Series List s Use the code to identify which series list you need. Each list is arranged by country, date and file number. Look for the file number on the right of the series list, and note the corresponding number in the left column. This number, prefaced by the Series number and Department, is used to order the document. If cards do not give file numbers, look at the FO 566 series list to find the relevant register of general correspondence.