While browsing through the manual, I saw the last section called "Notes" which you can freely edit to whatever you want. I think that's a pretty neat idea if I want to remind myself some things (like "Remember to use your special manual command hack!!"). But it seems like it's a weird place to put it under Manual. It's also laborious to have to go into manual file to edit there, so why not make it as one of the option tabs (to save a click, and to make it more stand-out) which you can edit and save your notes in-game? And if you open up the option with saved notes, the Notes tab can flash in a similar way as the flashing News tab.
I'm sure this is very low priority (does anyone really use them?), so it's not a big deal if it doesn't work.