Comment by QuantumNomad_
11 hours ago
They might be referring to this kind of thing:
> The first appearance of reversed DNS strings predated the Internet domain name standards. The UK Joint Academic Networking Team (JANET) used this order in its Name Registration Scheme, before the Internet domain name standard was established. For example, the name `uk.ac.bris.pys.as` was interpreted as a host named `as` within the UK (top level domain .uk)
from the History section of https://en.wikipedia.org/wiki/Reverse_domain_name_notation
But I don’t know if uk.co.somethingsomething did or did not exist at that time. Or if it was only introduced after the Internet domain name standards we use today existed and so was .co.uk from the beginning.
Oh, uk.co definitely existed for companies. The other 2nd-level domain (besides the academic uk.ac and uk.co) was uk.mod (Ministry of Defence), equivalent to the US .mil. And then, because life is never this simple, things appeared that were neither universities nor companies nor military, so uk.bl was given to the British Library. There might have been others as well, I don't remember.
Back then the code in various pieces of software had hand-written exceptions for domain processing. The joke was that all Computer Science departments in the UK (uk.ac.university-name.cs) ended up in Czechoslovakia.