I only take notes on paper very sporadically, and not in a very systematic fashion. To not make my notes more confusing than necessary, I remove pages that are no longer applicable. I just tear them out. The result is not pretty, and I suspect my note books will fall apart eventually. Have a bunch of small RITR that I use for now, but for the next round I should either improve my note taking to not require removal of pages, or find note books that are prepared for it.