Honestly it can look like a lot of different things. You could call in someone by saying something along the lines of
"I feel uncomfortable about what you just said, because..."
or "I used to agree with your perspective, but it changed when..."
or "I feel differently about that issue. Can I share my perspective? "
or you might even just model what they could have said in a reply or simply ask them whether they think others might perceive that comment as nice or welcoming or inviting or how someone of x background might get upset seeing something like this
question for you, if you don't mind. you mention users 'calling in':
"I think the community has already done a wonderful job self-moderating and calling people in, that is to say, encouraging nice behavior."
what does that look like to you in a public discussion format like beehaw? i read the piece that you hyperlinked, and maybe this is just my ignorance showing, but i still don't know how this looks when all of the discussion is primarily 'one-to-many' as opposed to 'one-to-one'; for lack of better phrasing.
save