I usually read my books on my iPad or my iPhone and occasionally I'll hop on my MacBook Pro. One thing I like about doing it on the i-devices is that you can just touch and swipe in order to highlight/underline/markup the text. Then, if you want to make a note, you just tap the underlined text and it lets you make a not (without making it a community not. I just figured out (about 10 minutes ago) how to underline on the computer, but now I'm not seeing how to make a note without making it a community note. Help?