The tables are set up like the example below. Note I start with the PRC number. I realize this may present a problem to many, but the PRC catalogue is in my opinion the authority, although the JPS effort seems to have the most information, to include paper, printing, and production varieties. The Yang and Gibbons catalogues are the easiest for me to use. I certainly do not mean to take anything away from any of the catalogue makers. Information is hard to come by, and honest information is even more difficult. But now I think we have turned a corner and are on the road to looking for and at what is genuine. No worthwhile endeavor is without pitfalls and detours.

As the prices of these stamps rise, be aware that there are many forgeries, many bogus issues, many caveats. Any expensive LAS should be expertized by a reputable authority.