You'd need a link for people to see the original content too so you'd want to include a link to one of the archive sites I guess (as a second best source for an

You'd need a link for people to see the original content too so you'd want to include a link to one of the archive sites I guess (as a second best source for an ephemeral post). It's odd but there are citation patterns for websites, wonder if they include a standard for including archives of sources not available at time of writing.