It's my fault (not the IA), I thought I'd got all newsgroups but must have missed some. I just checked the main newsgroup list and it's incomplete, for some reason.

My plan though, is to dust off the old code, get a complete list of groups, get them, and then make it searchable.

Sorry about that, I didn't check. This was all done in 2013. Basically, I wanted to build a search engine but indexing the newsgroup posts (for header and text body search) would take too long. I abandoned it, then in 2016 I sent it to the IA.

So, I only just found out it's lacking a bunch of groups, 5 years on...