Clarify read-only nature of IRC MODE command
While you do a good job of stating that the IRC interface deviates from the RFC, as well as where and how it deviates from the RFC, it may be beneficial to specifically call out the deviation that the MODE command is server-generated (read only), instead of being a keyword that can be generated by a client.
In other words, my bot cannot issue its own "MODE #channel +o nickname" command via the IRC interface (like it can on IRC), it can only receive notifications from the server that the server has sett one of those modes. One sentence covering that might save someone a day or two of troubleshooting and experimentation! Thanks

Thanks for the head’s up!
-
eggdroptest commented
On further investigation, and comments in the forum at https://discuss.dev.twitch.tv/t/is-mode-still-shown-to-irc-clients/24942/9 , maybe the MODE command doesn't even work anymore? I have not seen it in any of my testing. Your apparently very-loyal twitch developer base seems surprised when I expected this to work in the manner described in documentation :) Maybe this command is no longer supported and needs to be removed entirely from the documentation? Thanks again for looking into this. I'm happy to help test anything if it will help, please let me know. Thanks!