Behaviour of @ mentions in comment threads

[trichoplax]

Not exactly a bug, just a need for clarification of what the correct behaviour should be when someone uses an @user mention in a comment in a thread. This is currently unclear (without testing to see) when the user being mentioned has explicitly unfollowed the thread.

I raised a concern in a comment on another issue and then decided to raise it separately to avoid it getting lost.

Wording reproduced here:

Do we have a defined list of things that pings should be expected to do?

If you are following a thread (either automatically through being the author of the thread or post, or due to manually following) then you should be notified of every comment. If you unfollow a thread then you should not be notified of any comments. If you have never followed a thread you should not be notified of any comments.

Is there reason to expect mentioning a user to override any of those behaviours? If I am already being notified, presumably the mention should have no further effect, and is simply to inform anyone reading the thread that the comment is aimed at me? If I unfollow, should a mention be able to override that? I assume a mention cannot ping someone who has no relationship with the thread (has never followed), but is there the expectation that people who unfollow can still be reached with a mention?

It seems it might be useful (whether in this issue or another) to make 2 things explicit:

• When a user unfollows, inform them that they will / will not be notified when someone mentions them.
• When someone mentions a user who has unfollowed, inform the mentioner that the mentionee will / will not be notified by it. This might make a user's following status sometimes public - is this a concern?

[ArtOfCode-]

Mentions have their own list of users who can be pinged, which includes but is wider than thread followers. If someone has been involved in a post I would expect them to be reachable by ping, even if they've unfollowed a particular thread.