Earlier this year I asked for any information regarding this -
I have been to the National Archives and can report that
WO 162/341 Report of the Prisoners of War Information Bureau 1914-1920
contains a list of Internment Camps as at 31st January 1919.
This is clearly the reference POWIB that was against some of the entries on the list I found at Tonbridge Library a few years ago.
The Report was held previously in the War Office Library and describes the procedures of the Bureau, so there is no real information about how camps were run etc. The Report contains copies of the many and various forms and cards produced by the Bureau. It is really a manual of how to run such an organisation in the event of another war!
Further - forum member Stenoyab was asking about Belmont Camp and speculating it could have been in Kent. In fact it was near Sutton, Surrey.
The main camps in the list were:
Catterick, Yorks (expanded from a working camp under Brocton)
Frongoch, nr Bala, N Wales
Handforth, Rubber Works, Handforth, Cheshire
Pattishall, nr Towcester, Northants
Shrewsbury, Abbey Wood, Shrewsbury
Stobs, Hawick, Scotland
Many other locations were recorded as being working camps 'under' one of these. Also there seems to have been a system of Agricultural Depots 'under' the main camps with Agicultural Groups under them. Other locations included hospitals.
In HO45/11025/410118 Report of the Directorate of Prisoners of War (published by WO September 1920, but not publically I think)
In January 1919 -
Total POWs UK 128,043
Total France 199,840
Total worldwide 507,215 (463,907 combatants, 43,308 civilians)