Open access watch-out list
Well, once open access journals started, some – well – individuals or groups – figured this was possibly a good thing to get in on, extracting publication fees from scientists desperate to get their articles in print. There’s always those cheats. And no good honest signal to go by.
Scholarly open access keeps a list of those journals that they suspect are predators. It is not a perfect list, as they accnowledge, but can be used as proxy detectors.
(I’m reading too much evolution).