Stamps
- 341
- Scandinavian Collectors Club
- Organization is devoted to research about and education regarding the stamps and postal history of Denmark, Greenland, Finland, Iceland, Norway, Sweden, and other related territories.
- 342
- Society for Costa Rica Collectors
- Group is interested in the study of the Latin American nation's postal history.
- 343
- Society of Israel Philatelists
- Group promotes collection of Israel's stamps through a bimonthly publication and educational slide shows.
- 344
- Americana Unit
- Collectors' group specializes in stamps of all nations that honor the United States of America by depicting individuals, landmarks, and other subjects directly related to the country.
- 345
- Astro Space Stamp Society
- Group caters to collectors of space-related stamps, postcards, and covers, and publishes a quarterly magazine.
- 346
- Chemistry and Physics on Stamps Study Unit
- Collectors in group specialize in stamps picturing scientists and science-related topics.
- 347
- Chess on Stamp Study Unit
- Group of collectors specializing in stamps, postmarks, and other chess-related philatelic items provides a quarterly newsletter for members plus checklists for all collectors.
- 348
- Christopher Columbus Philatelic Society
- Group of collectors specializes in stamps and other philatelic material commemorating the voyages of Christopher Columbus.
- 349
- Ebony Society of Philatelic Events and Reflections
- Organization promotes the collection of stamps honoring African Americans and related topics, and encourages stamp collecting by African Americans.
- 350
- Europa Study Unit
- Club promotes the collection of stamps featuring subjects related to the economic, political, and social integration of Europe.
- 351
- Graphics Philately Association
- Club members promote the collection of stamps honoring books and the history of printing.
- 352
- Lions International Stamp Club
- Group promotes the collection of stamps and covers honoring Lions Club International and Lions-related subjects.
- 353
- Mathematical Study Unit
- Club members collect and share information about philatelic materials related to math, mathematicians, and computers.
- 354
- Penguins on Stamps Study Unit
- Promotes the study and collection of philatelic material picturing or related to penguins, including stamps, postcards, postal stationery, and ephemera.
- 356
- Space Topic Study Unit
- Members of club are devoted to the study of covers and stamps related to space themes.
- 357
- Stamps on Stamps Collectors Club
- By promoting communication between members and publishing a newsletter three times per year, organizations supports collectors of stamps picturing stamps.
- 358
- Wine on Stamps Study Unit
- Group specializes in thematic stamps related to wine, wine production, and grapes, and publishes a quarterly journal with articles about such stamps.