Elephants remember: companies using "block lists" to not rehire some employees

Every organisation does, whether it's a formal list or not.

Government agencies have stricter requirements than private companies when it comes to flagging people as not-for-rehire, but not even they will welcome you back if you get fired for cause.

Related Meta keeps 'block' lists of ex-employees – and even a VP can't get you off them (43 points, 17 days ago, 20 comments) https://news.ycombinator.com/item?id=43280435

I understand many do not always have a choice, but if one did, why would they ever willing go back to a former employer?

Did it once (after a few years and major org changes). It turned out to be a great way of rediscovering why I left in the first place.

People change, orgs change, managers change or leave.

I left a nice job (willingly, on friendly terms) to experiment with a new line of work and to take some time to care for myself. I was happy to return a couple years later.