the only protocol-centric affixes i’ve ever had on my domains were either ‘irc.’ or ‘mail.’ (and for a long time mail.teleri.net had an HTTP interface!). i’ve always thought the http was implied by reachability on port 80/443. www is such a weird anachronism
imagine if we had something like 8192 or so well known services that mapped to specific ports. we could put them in a file and just ship it in the OS. it would be so wild