> If you don't leave enough space you'll have to shift all the books after that letter. This is what card files were originally invented for— number all the sh

> If you don't leave enough space you'll have to shift all the books after that letter. This is what card files were originally invented for— number all the shelves, put your new book wherever there’s room, and put a card with the title and shelf number in a sorted drawer. When you get rid of the book, get rid of the card.