Backstory: Bored? Try the matchcover collectors club.

Whenever two or three people gather together, they're likely to form an association.

The Encyclopedia of Associations covers more than 22,000 national organizations and 115,000 regional, state, and local groups. I'm intrigued by associations of people who are passionate about a hobby or an avocation, be it tractor pulls, toothpick holders, or boomerangs.

Bird and bird-watching groups, for instance, include the American Dove Association, the American Ostrich Society, and the North American Loon Fund. Other animal watchers congregate under the banner of the Cow Observers Worldwide, which also promotes the collecting of cow memorabilia.

The aggregation of collectors includes the Cracker Jack Collectors Association, the American Matchcover Collecting Club, and the Eggcup Collectors Corner. Enough vexillologists – flag collectors – exist to support an International Federation of Vexillological Associations.

Sports buffs congregate to pursue bocce, croquet, kite flying, darts, falconry, shuffleboard, and jousting – latter-day knights on horseback spearing small rings with lances. Rope-jumping organizations include the American Double Dutch League, with a staff of three and a membership of 40,000. United States Arm Sports promotes arm-wrestling in weight ranges from bantamweight to heavyweight. They also promote wrist-wrestling. (Wrist-wrestling?)

Does the existence of the US Amateur Tug of War Association mean that somewhere there's a professional tug of war association?

The International Polka Association should consider having a joint convention with the three organizations of accordionists.

The 543 members of the Institute of Totally Useless Skills are "devoted to the obtainment of nonpractical skills," in which they include spoon playing, eye crossing, and yodeling. But don't say that to any of the 500 members of the Ethel Delaney International Fan Club, which "promotes the history and career of Delaney and country music, especially yodeling."

Unicorns Unanimous, alas, is now defunct.

• Dale Roberts, a college career counselor, lives in Asheville, N.C.