I agree there's nothing specific about prisons in BS 7671 - so from that point of view general requirements would apply - so by default BS 1363 sockets would typically be the preferred option.

Prison authorities might have their own views however (like the NHS do with their HTMs)  - I might imagine there would be some restrictions on say sockets in unsupervised areas (you wouldn't want to give homicidal types access to a potentially lethal voltage for instance) or be subject to remote switching or that sort of thing.

   - Andy.

AJJewsbury said:

Prison authorities might have their own views however (like the NHS do with their HTMs) 

Some of those facilities are subject to HTMs.

I am sure I was once told that in HMPs tamperproof fixings are needed to secure lids and offer protection to the contents of electrical accessories.  Might be worth getting in contact with the HSE there will be lots of other criteria which will need to be met like anti Anti ligature design and Vandal resistant accessories

Peter - assuming this is a prison in England or Wales? You need to get the MoJ's Technical Standards, which describe the requirements for the installations including the required specification of the outlets.