@andros Thanks for consolidating a lot of good ideas. Especially how you have deiced to just extend the mention syntax for location-based treads. This might even be backward compatible with older (pre-yarn) clients. What about using Z for UTC +00:00- is that allowed in your specs? Regarding url = I would suggest to only allow one and the maybe add url_old = or url_alt = !? I'm still not a fan of a DM feature, even thou it helps that i have now been split out into a separate feed file. Instead if would suggest a contact = field for where people can put an email or other id/link for an established chat protocol like signal or matrix.

@andros About the URL, since it no longer used for hashing there might be no need to change it. I agree that we keep all the parts that already are out there for the most parts. Instead of a contact field you could also just use links like: link = Email mailto:user@example.dk or link = Signal https://signal.me/sthF4raI5Lg_ybpJwB1sOptDla4oU7p[...]