I recall an early episode of Hikaru No Go where a player has a joseki book at a tournament game, and while it was considered a sign of weakness, it wasn't against the rules.
Sometimes I refer to Sensei's Library during games. I tend to play more on instinct and direction of play, and haven't memorized very many joseki, but the correspondence nature of this site lends itself to being a good way to learning without holding up a game.
I know professionals will confer with their students between the days of matches, so I don't really consider this cheating. Joseki alone won't win a match, because you need to know which direction to play and what to do with it afterwards.
> Is it against the rules? Is it against etiquette?
No. It is part of the game. But the proverb wisely advices: "Learn joseki and you will lose 3 stones." It is really a bad idea to play something you don't fully understand just because you have seen it played by superior players. You can become shodan (my level) with really just elementary joseki understanding (my case). Then, study joseki: which means try them against stronger players to see what the usual variations are. I don't like studying, and are too old to have any go playing illusions, but younger people who want to become really strong study a lot when they are already strong. That's what I have seen.
We all learn differently, but I fully agree. I know very few joseki, just a couple of the basic approach and invasion sequences. It would frustrate some of those trying to teach me, when they'd say "that's not joseki," and I'd say "I don't care." I got to 4k through knowledge of shape and study of direction of play. I play by instinct and feel.
But this format of game lends itself to the study of joseki, and is a way I can start to learn them. Glad to know I wasn't wrong in thinking it was part of it. I'm okay with losing three stones. :)
Little Golem