In 1929 a new system of registration was introduced for all Prison Commission headquarters files. As from 1929, the prefix 'A' was used for all administration files. These comprised all headquarters papers apart from personal files which were registered under the prefix 'B' for Borstal inmates (and prison inmates who had previously served a Borstal sentence) and 'P' for prison inmates. In 1959, it was decided that the 'A' series covered too wide a field and the following revised classification was adopted.
A : Administration, general
C: Directorate of Industries and Stores
D: Directorate of Works
E: Establishment Division
F: Finance
The Prison Commissioners Dissolution Order 1963, made under section 24 of the Criminal Justice Act 1961, came into operation on 1 April 1963 and transferred responsibility for penal establishments to the Home Office. The Prison Commissioners and their staff were thereby integrated into the Home Office and became the Prison Department. The scheme of registration described above continued in use for a few years after integration, but was gradually phased out with the introduction of the 'symbol' system of file registration in 1966.
The system is as follows:
General Files
PDG: Prison Department: prisoners general
DIS: Industries and Stores (from 1969)
DIF: Industries and farms (from 1981)
PIF: Prison Service Industries and farms (from 1985)
D: Works
PRG: Prisons: general matters
ETG: Prison establishments: general matters (from 1969)
DPG: Directorate of prisons personal services: general (from 1980)
DPF: Directorate of prisons personal services: financial
Personal Files
B: Borstal Inmates: personal
P: Adult prison inmates
PDP: Prison Department: prisoners personal (from 1967)
ESP: Establishments: personal matters
NI: Establishments: personal matters (from 1973)
ETP: Prison establishments: personal matters (from 1959)
DPS: Directorate of prisons personal services: general (from 1980)