To Nick Artimovich and hundreds of other Americans, today is the equivalent of Christmas, the Fourth of July and Halloween rolled into one. For this, Flag Day, is the one day of the year public attention is focused upon their humble corner of the scholarly world -- vexillology, the study of flags and seals.

Vexillogists have to make the most of it. They're not exactly a hot property on the morning news shows.

"Of all the sciences, it's probably one of the more obscure ones," said Artimovich, an engineer for the Federal Highway Administration.

Artimovich, a Columbia resident, and fellow flag student Thomas Carrier, of Arlington, hope to change that with a vexillology road show of sorts. Both men are members of the North American Vexillological Association, an international organization of flag buffs with about 350 members.

The duo -- think of them as the Masters and Johnson of vexillology -- will run a flag-evaluation clinic Saturday at the Columbia Mall designed to tell the public everything it wants to know about flags.

Take, for example, the story of the pirate skull and crossbones. The original pirate flag was solid red. Ships carrying passengers or crews with contagious diseases flew the skull and crossbones to warn other vessels not to board them. Pirate ships used the flag as a ruse to avoid capture.

Even the Land of Oz has a flag, Carrier said. "One of our members found the description in L. Frank Baum's book 'The Wizard of Oz.' " The flag contains four colors, one for each of Oz's provinces.

The word "vexillology" is derived from the Latin vexillum, a square flag used by the Roman cavalry.

The field involves "a lot more than just recognizing different colors," said Artimovich, an authority on American flags who has collected 250.

Artimovich also reviews the flag display in the State Department's lobby to make sure the flags are current.

His contract with the State Department resulted from his discovery two years ago that the Haitian flag was outdated -- left over from the despised Duvalier regime.

Artimovich called the error to the attention of the State Department.

His timing -- from a vexillology standpoint -- couldn't have been better. The wave of democratization sweeping Eastern Europe is resulting in a host of new or revised national flags. The royalist crown, for example, has been restored atop the eagle on the flag of Poland, while the Soviet hammer and sickle has been stripped from the Hungarian flag. Artimovich delights in such changes; under his contract, he gets to keep any flags that become obsolete.

"I already got Romania," he says with the zest of a 10-year-old baseball card collector. "I'm looking forward to East Germany, with reunification."

Carrier specializes in U.S. presidential flags. The president of the United States has his own flag, said Carrier, a meeting planner for Wasington-based nonprofit groups. The presidential flag, similar to the U.S. Great Seal, features an eagle gripping olive branches and arrows inside a circle of stars. The flag carries some interesting anecdotes.

After he ordered the atomic bomb dropped on Japan, for example, President Harry S. Truman suggested adding a jagged bolt of lightning between the eagle's beak and claws on the flag to symbolize the United States' atomic might, Carrier said. The suggestion was never acted upon.

Carrier and Artimovich delight in shattering flag myths. The biggest, the two men say, is the belief that seamstress Betsy Ross designed the first American flag. Although Ross sewed some of the first flags, the designer of the colonial-era circle of stars was in all likelihood a New Jersey congressman named Francis Hopkinson. Artimovich cites, among other evidence, a 1780 letter Hopkinson wrote to Congress seeking a quarter-cask of wine as partial reward for designing the flag and the great seal of the United States.

Other vexillologists fiercely maintain that Betsy Ross designed the flag. "It's a raging debate in vexillology," Carrier said.

And one unlikely to be resolved soon.