If I like the book I'll write in the margins. If it's a second read lots of stuff let's put there, lots of spoilers.

I only really use pencil unless I'm copying something directly from another source and want it for reference.

I'll sometimes make pencil marks in library books. No spoilers or anything, but amusing notes to future readers. I'm a monster.

Do you do it to library books?

Do you use pen?

Do you write in the margins of books? This would include notes between lines, underlining, leaving note cards in the pages, ebook notes, etc.

@catsalad

This is the world we all want!

Vote for me and I will decree that all kitchen appliances with a time display will be required to have a gnss module that always displays the correct time even after power outages.