h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

One type of 'bookmark' that doesn't get a mention is the Post-It note (or other temporary adhesive slip of paper). These can be made by tearing a strip off a large Post-It note, or you can buy a pack of different coloured strips that have been sized for this purpose. They are great for marking a place in a textbook or other reference work. It's possible that these were omitted because Post-It is a brand name and the BBC doesn't advertise.

Another type that has been neglected is the magnetic bookmark. These are becoming more common. They're a strip of folded cardboard with two magnets, one at each end. The bookmark clips over the edge of the page and can be used to mark exactly where the reader had got to on that page. Unlike normal bookmarks, these are best positioned away from the spine.