@[email protected] @by_[email protected] since tel: is extremely fraught, especially nowadays with insane phone spam etc, a Signal/WhatsApp/etc address might be a good alternative example?
I particularly like the "established encrypted messenger" example because the wf->[rel=messenger]-> lookup could get Fedi encrypted DMs "for free."
(obviously lots I'm glossing over that make it more complicated, but in theory it'd be less complicated than many alternatives)
@[email protected] @by_[email protected] (one thing to note is that it's not possible to declare an alias, e.g. a phone number in a wf or other profile, and then use that alias in reverse as a way to look up the original profile. I mean, one could do it, but with questions of identity at play it would be an incredibly very extremely bad idea to do that from every conceivable security perspective.)