Stamps
- 201
- Cover Collector Circuit Club
- Organization facilitates the exchange of covers between collectors around the world.
- 202
- Errors, Freaks & Oddities Collectors' Club
- Group focuses on stamps that exhibit evidence of production errors such as misprinting or misperforation.
- 203
- First Issues Collectors Club
- Organization promotes the collection of the first stamps issued by any country or stamp-issuing entity.
- 204
- International Machine Cancel Society
- Organization is dedicated to the study of machine postal markings plus the history of machine inventors and patents.
- 205
- King George VI Collectors Society
- Group studies the stamps issued by members of the British Commonwealth from 1936 to 1952 during the reign of King George VI.
- 206
- Meter Stamp Society
- Group of collectors is dedicated to the study of postage meter stamps, personalized photo stamps, and other stamps printed on-demand.
- 207
- Metropolitan Air Post Society
- New York-based club's members focus on airmail postal history and event covers.
- 208
- Military Postal History Society
- Organization's members study philatelic materials related to wars, including prisoner-of-war letters, patriotic covers, censored mail, and military postal markings.
- 209
- Mourning Stamps and Covers Club
- Collectors in club specialize in the study of black-bordered covers used to send mourning letters and cards in the 19th and 20th centuries.
- 210
- National Duck Stamp Collectors Society
- Organization caters to collectors of waterfowl hunting permit and conservation stamps.
- 211
- Post Mark Collectors Club
- Postmark collecting, the National Postmark Museum, and publishes a monthly bulletin for members.
- 212
- Postal Label Study Group
- Club's members collect registration and express labels, airmail etiquettes, official seals, and other labels used on mail.
- 213
- Postal Stationery Society
- Group focuses on the collection and study of stamped envelopes, postal cards, and other postal stationery items from all countries.
- 215
- Precancel Stamp Society
- Supports collectors of stamps bearing cancellation markings applied before the stamps were used to mail a letter or package.
- 216
- The Perfins Club
- Organization's members collect stamps perforated with designs, initials, and numerals.
- 217
- United Postal Stationery Society
- Group is devoted to the study and collection of postal stationery including stamped envelopes and postal cards from all countries.
- 218
- Universal Ship Cancellation Society
- Club promotes the study of the history of ships in the U.S. navy and other maritime organizations and the postal history and postal markings used on those vessels.