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. American Topical Association - Promotes topical and thematic stamp collecting by publishing reference works and checklists and organizing the National Topical Stamp Show. International Machine Cancel Society - Organization is dedicated to the study of machine postal markings plus the history of machine inventors and patents. United Nations Philatelists, Inc. - Group is devoted to the collection, study, and exhibition of the stamps and postal history of the United Nations. American First Day Cover Society - Organization supports first day cover collectors, cachet makers, and dealers. First Issues Collectors Club - Organization promotes the collection of the first stamps issued by any country or stamp-issuing entity. Post Mark Collectors Club - Postmark collecting, the National Postmark Museum, and publishes a monthly bulletin for members. Auxiliary Markings Club - Group studies covers bearing handstamps, machine markings, labels, manuscript notations, and other indications that the covers received special attention in the mails. Art Cover Exchange - Facilitates trade of covers bearing hand-drawn or printed art and other decorations. American Air Mail Society - Promotes aerophilately through publications, member auctions, and an annual meeting. Wreck & Crash Mail Society - Group specializes in the collection of mail that was delayed or damaged due to accidents. Postal History Society - Group dedicated to studying letters, covers, and other mail from around the world publishes a quarterly journal and reference books, and hosts an annual conference in England. Postal Stationery Society - Group focuses on the collection and study of stamped envelopes, postal cards, and other postal stationery items from all countries. American Ceremony Program Society - Organization promotes the collection of commemorative programs and related materials produced to complement new stamp issues. American Revenue Association - Through a quarterly newsletter, handbooks, and catalogs, this organization supports collectors who specialize in revenues and other non-postal stamps. American Society of Polar Philatelists - Group collects stamps and covers used in Earth's polar regions, and publishes a quarterly magazine containing articles about such material. Armenian Philatelic Association - Group focuses on Armenian philately and other nations' stamps that are related to Armenia. Christmas Seal & Charity Stamp Society - Organization publishes catalogs about and supports collectors of Christmas seals and other charity stamps from around the world. Cinderella Stamp Club - Collectors' association encourages the study of all non-postage stamps including revenues, telegraph stamps, seals, and poster stamps. Cover Collector Circuit Club - Organization facilitates the exchange of covers between collectors around the world. Errors, Freaks & Oddities Collectors' Club - Group focuses on stamps that exhibit evidence of production errors such as misprinting or misperforation. Meter Stamp Society - Group of collectors is dedicated to the study of postage meter stamps, personalized photo stamps, and other stamps printed on-demand. Metropolitan Air Post Society - New York-based club's members focus on airmail postal history and event covers. 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. 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. National Duck Stamp Collectors Society - Organization caters to collectors of waterfowl hunting permit and conservation stamps. The Perfins Club - Organization's members collect stamps perforated with designs, initials, and numerals. Postal Label Study Group - Club's members collect registration and express labels, airmail etiquettes, official seals, and other labels used on mail. Poster Stamp Collectors Club - Caters to collectors of stamp-like labels issued to promote events. United Postal Stationery Society - Group is devoted to the study and collection of postal stationery including stamped envelopes and postal cards from all countries. 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. Precancel Stamp Society - Supports collectors of stamps bearing cancellation markings applied before the stamps were used to mail a letter or package. Civil Censorship Study Group - Collectors in group focus on mail that was censored while in transit. Maximum Card Study Unit - Group shares images of members' postcards with matching or related postage stamps. The Perfin Society - Group based in the United Kingdom focuses on stamps with perforated initials. Mailer's Postmark Permit Club - Assists individuals who wish to cancel the stamps on their own mail by providing instructions on how to obtain mailer's postmarks and maintaining records about such markings. Local Post Collectors Society - Organization promotes the study and collection of stamps issued by modern local posts.