Books are theory so I guess not.
Is using a book for an opening cheating?
In live games it's cheating, in "daily" games it's ok.
https://support.chess.com/article/317-what-counts-as-cheating-on-chess-com
Not every post/topic with the word cheating is a discussion about it. Something like this was a rules question and allowed.
Research is a central pleasure of correspondence chess. Use MCO if you like. I’m using ECO, Chess Informant, and six linear feet of opening monographs on my shelves. I also have ChessBase Mega.
Did you see how many other were directly discussing cheating with no lock? Where were the mods there? And why is it that when I post something not about cheating but that briefly mentions it you are like a lightning to block the thread?
I tried to block you, but you beat me to it. There’s a site glitch that hides that option when someone blocks you. Harder to report you, too.
Want me to teach you the work-arounds?
online, is using for example MCO cheating? just for the opening?