The university halls that I lived in had those RCD sockets installed. The halls dated back to the early 60s - the sockets + Ethernet were installed in perimeter

The university halls that I lived in had those RCD sockets installed. The halls dated back to the early 60s - the sockets + Ethernet were installed in perimeter trunking. I suspect it was the cheapest option available to the university to modernise the electrical infrastructure inside the halls.