Function and purpose

This correspondence series records all security classified matters dealt with by the Department of Defence. This includes a large proportion of information-gathering and the information itself, policy matters, technical information about such things as armaments, manpower and deployment.

The series covers the period of the Second World War which increases the scope of the classified material covered by the series. Virtually all Defence administration correspondence during the war period came within the parameters of the classified series.

Following the pattern of the other Defence series, this series is organised as a subject classified folio registration multiple number system. This means that the subjects covered by the series were listed alphabetically and then numbered in sequence, 1-146. These numbers comprise the primary element of the registration number. These subjects are further sub-divided and numbered from 301-323, and these numbers form the secondary element of the registration number. From this secondary number this series derives its familiar name, the 'Classified 301' series. The third element is the running number allocated to each paper registered within each class. An additional   single number with a 'TS' (Top Secret) prefix was allocated to those files classified top secret. This number does not affect the multiple number system of arrangement of the series.

At the time when this series was raised, files as such were unknown. The items registered in the subject registration booklets (CRS A4398) were single papers received. When a second paper on a topic was received it was registered with a second 'third element' number and the first paper was brought forward and located with the second paper. In this way bundles of papers on the one topic would gradually accumulate as papers were constantly brought forward. They therefore do not have file titles or file covers for the first five years of this series.

After 1940 the practice of registering every paper received on one subject (ie giving each a new registration number) declined and the bundles of papers gave way to recognisable files. Papers were still 'logged' in the registration booklets underneath the initial registration. Because of the practice of bringing forward papers related to the paper registered a number of the 'files' in this series have papers registered in the predecessor, security-classified series, CRS B197, secret and confidential correspondence files, multiple number series, 1906-1936. These papers are readily distinguishable by their primary numbers 1801-2029.

A large proportion of these files are purely informational, consisting of papers on policy or briefing papers forwarded from the Department of External Affairs for circulation in Defence. These files have only a circulating minute on them besides the briefing papers. It should be noted that this series, while nominally classified, also contains files which are unclassified. After 1958 however it seems that the practice of keeping a separate security classified series was abandoned. Henceforth it seems that individual classified files in the main series were kept separately and controlled by a secondary control record, CRS A2552, Movement register and register of top-secret files, 1957-1974.

Finding aids

Consignment lists exist for this series.  Most, possibly all, items are registered onto RecordSearch as at March 2006.