I often add my own tabs, you can buy a box of a 100 for a few dollars at a office supply store, makes for quick reference look ups. Also use the post-it labels that come in tiny strips to highlight a particular notation I need.
"Buy the Book Before You Buy the Coin" - Aaron R. Feldman - "And read it" - Me 2013! ANA
Life Member #3288 in good standing since 1982, EAC Member #6202, NBS Member, 2¢ variety collector.