Primary and specialist sources used to shape the site’s evidence-first approach.
Institutions and references
- Smithsonian National Postal Museum: stamp tools, terminology, postal history, and collection records.
- American Philatelic Society: collecting education, estate guidance, expertizing resources, and warnings about unrealistic value claims.
- The Philatelic Foundation: expertizing and grading frameworks.
- USPS: current U.S. stamp issues and official postal information.
- eBay: active marketplace categories used for affiliate search routing.
Editorial standard
RareStamps.co does not reproduce proprietary catalogs or assign catalog numbers from photographs alone. Country, issue, physical evidence, condition, postal use, and specialist literature must agree.