The catalog lists each stamp that appears in the various topical collections. Some of the stamps appear in more than one place, and so will appear more than once in the catalog. I have checked all the links for accuracy but if  you find errors, please let me know.
     The Michel and Gibbons numbers for map stamps have been added based on the Checklist of the CartoPhilatelist Society. The Gibbons numbers end in 1993-94 because of the catalogs used. Michel also ends about the same time. Those will be updated as they become available to me.
     If you have a correction or addition to these numbers please let me know. I will be happy to make additions and corrections.