Standardisation is weird in IRC. From what I've seen, most of it that has happened has been the result of one group implementing their custom command/extension and then a bunch of other vendors implementing it in the same way (as well as all the interesting politics behind it all). There's a surprising amount that's been mostly-standardised over time, and not just from formal standards groups like the IETF or IRCv3.

Related, I've been working on these sites for a while which I hope can be useful: http://defs.ircdocs.horse/ http://modern.ircdocs.horse/

Still, it's been really interesting to get into. It's nice seeing how things have gone so far and how they're going forward (and digging into the archives is always fun).