I am doing some work on a German soldier who served in 262 R.I who was captured on 9 April 1917. In docs provided by the Red Cross I can see that he was interred at 'Co.81' with the number '264' underneath.
I would find out more if I could see the big ledgers – the 'Registres' at the ICRC in Geneva. However, that will have to wait until the digitisation project is completed (or even started).
In the interim, does anyone know what camp this reference may relate to?