The term Back of the Book generally refers to those stamp issues that have appeared in the back of the Scott Standard Postage Stamp Catalogue. The catalog itself is released in volumes, each covering a set of stamp issuing nations. So, U.S. &back of the book& stamps would appear at the end of the United States section. These stamps also have one or more letters appearing before their catalog number. An example of a regular postage stamp issue would be U.S. 4119. An example Back of the Book stamp would be U.S. C7. The &C& is the notation for Airmail stamps.
So, why do they appear in the back of the catalog? Are they not as popular, valuable, or collectible? No. They are more seldom seen by the general public. But the reason they appear in the back is that they require special categorization. Their use differs from regular issues. And their costs are applied differently. For example, Semi-Postal stamps were and can be used for sending a regular letter to a regular U.S. destination. But they carry a special surcharge that is donated to charity. Recently we wrote a bit about a couple of semi-postal stamps — the 2001 Mongolia B27-28 Unity Against Terrorism Stamp and the U.S. B1 Breast Cancer Research Stamp (which has raised an astounding $83.9 million for breast cancer research).
One shouldn’t think of the back of the book as synonymous with bottom of the barrel. Nor should one think of all back of the book stamps as particularly rare. After all over 1 Billion of the Breast Cancer Research Semi-Postal Stamps were sold! But while all postage stamps are unique and fascinating, back of the book stamps are just a little more special. Do you have any in your stamp collection?