I agree that it would be nice to have fine-grained notifications
synchronization across clients.
While looking to see if XMPP have such XEP, I found
these extensions from Tigase that might be helpful in writing an official XEP:
https://xeps.tigase.net/docs/push-notifications/filters
I think this covers the specific use case of a push server, which
unfortunately limits its scope.
For MUCs, it is a perfect fit for XEP-0402: PEP Native Bookmarks
<extension>, in the spirit of XEP-0469: Bookmark Pinning? eg:
<itemid='theplay@conference.shakespeare.lit'><conferencexmlns='urn:xmpp:bookmarks:1'name='The
Play's the
Thing'autojoin='true'><nick>JC</nick><extensions><notifyxmlns='urn:xmpp:filter-notifications:0'when='always'/></extensions></conference></item>
with when= taking 3 possible values "always", "never" and
"on-mention".
For contacts, a PEP (XEP-0163: Personal Eventing Protocol) node would
work. wouldn't it?
<publishnode='urn:xmpp:filter-notifications:0'><itemid='that-damn-guy@annoying.server'><notify
when='never'/></item></publish>
I am not entirely sure about the real life use-case for muting
notifications from a contact when you can just block them via other
ways, but maybe I'm just not imaginative enough. :)
List, any feedback on these ideas?
-- Nicolas