I own two immense shelves that I want to put 12 section of books/folders on. How do I sign the section? I don't want to put sticky labels on the shelves themselves because...

I don't want to put sticky labels on the shelves themselves because of aesthetics and the fluid quality of the sections (they can grow or contract). I'm thinking give or take a few something like tab, but how would I get them to stay contained by place? The shelves are too deep for most tab and they will lose their place.
SF Bay Area- Christmas lights installed for me?
Answers:    There are little plastic things you can buy at the hardware store that allow you to put some sort of paper contained by the little plasitc space. So just buy the plastic things, write something on the dissertation, and insert the paper into the plastic space.