A record office was established in the Admiralty in 1809. By the mid nineteenth century a system had been instituted within it whereby the larger, more important, files were bound together into a single volume or case. ADM 116 consists of many such cases, continuing the earlier series in ADM 7. Each case was given an Admiralty case number by which it was then referred to in the Admiralty digest and other Admiralty sources and which should not be confused with the later piece number.
The key to Admiralty cases (part 1) shows that while most cases fell into a 'main' series several smaller case groups were also created. In 1932 papers designated as secret were separated out forming the '00' group. Two years later it was felt that all papers originating in the cabinet office should also be segregated, four new case titles thus being adopted. These became the 'cabinet' series for those files containing cabinet minutes, 'cabinet committee' series for files from cabinet sub committees, 'defence' for papers from the Committee of Imperial Defence and 'communications' for papers from the Imperial Communications Committee. Finally a group of files dating from 1870 were prefixed with the letter 'F' while a single case also remains retaining the reference 'H&A', abbreviating 'Honours and Awards'.
Secretariat papers, when passed to the Admiralty Record Office, were then 'digested' under a relevant subject heading. The tables of heads and sections under which the correspondence of the Admiralty was digested were originally set out in 1809, with later revisions in 1843, 1881, 1909, 1935 and 1963. Each heading was also given a corresponding digest code number. For example: Academy and Education (1); Accidents and Casualties (2)
As a result of the Admiralty's case and digest systems the catalogue to ADM 116 must necessarily incorporate three separate sets of numbers, that is the case number, the digest code number and the later piece number.
The arrangement of the catalogue to ADM 116 is as follows:
Pieces 1-3624 (part 1), arranged by piece number
Pieces 3625-5460 (part 3), arranged by subject (1963 digest)
Pieces 5461-end (part 4), arranged by subject (1935 digest)
The subject index in part 2 is the tool which any reader should use who wishes to make a subject approach to ADM 116. The subject index also provides relevant case numbers which can be found alongside the subject headings. From here the key to Admiralty cases then cross refers case to piece.
It should be noted that the subject index follows the headings of the 1963 digest. Unfortunately the catalogue itself uses headings from both the 1935 and 1963 digests. In an attempt to simplify the digest system an index to subject headings has been prepared to show all possible variations. This index can be found at the front of all four parts of the catalogue.
Finally although only the first part of ADM 116, pieces 1-3624, is arranged by piece, a key to pieces has been provided to cross refer the piece number to case and digest numbers for the remainder of the series. The key to pieces can be found at the front of part 1.