Board Thread:The Panopticon/@comment-1296654-20190726133841/@comment-1296654-20190803114321

https://grammar.yourdictionary.com/grammar/style-and-usage/what-s-the-difference-between-etc-and-et-al.html

https://www.grammarly.com/blog/et-al/

I don't see much evidence of them being interchangeable, having only ever seen "et al" as being used for people and never for other things until visiting this wiki.