Additions_to_our_catalogs
What should be listed in a catalog?

Found something that is not in the catalog? Here is how to report it.

19th Century US Stamped Envelope Catalog Corrections:

20th and 21st Century US Stamped Envelope Catalog updates/corrections: 20th and 21st Century US Stamped Envelope Catalog supplemental information: Stamped Envelope and Wrapper Specimens of the United States

Postal Stationery of Mexico Errata (August 2018)