[gs17]

The first Doe and Smith example I could give that to (the title is real and the arxiv ID they give is "arXiv:2401.00001", which is definitely placeholder), but the second one doesn't match a title and has fake URL/DOI that don't actually go anywhere. There's a few that are unambiguously placeholders, but they really should have been caught in review for a conference this high up.

[mikkupikku]

How does a "placeholder citation" even happens? Either enter the citation properly now, or do it properly later. What role does a "placeholder citation" serve, besides giving you something to forget about and fuck up?

I do not believe the placeholder citation theory at all.