They come into every newspaper office regularly -- the calls, the letters, the elaborate publicity releases: Some guy has buried himself alive out in Delaware, going for a record of 122 days; a Connecticut man plans to celebrate his 60th birthday in three continents on the same day; this kid has been bounding a basketball for 60 hours; the world champion backward-walker is on the road again.

All they want is immortality -- in the Guinness Book of World Records.

Everyone knows the Guinness Book. It is getting more famous than the Stout. Launched in 1954 with an edition of 187,000 copies, it is now right up there with the Bible, having sold a total of 30 million copies.

Founded when the brewery director Sir Hugh Beaver shot at a golden plover one day while hunting and missed --fastest bird in the world -- the Guinness Book rapidly became an institution in the hands of those gifted twins, Ross and Norris McWhirter. Ross was murdered at 50 in 1975 by Irish terrorists, but his twin carries on. With a staff of 20, including only about six editors, he completely reworks the 688-page volume every year.

Even if no new records were added, nearly half the existing ones must be changed each year: The longest mustache grows another inch. the tallest tree another foot, and so on.

Those new records are something else. Now collected in a special short station titled "Stunts and Miscellanceous Endeavors," they range from Apple Peeling (longest peel: 130 feet, 8 1/2 inches) to Yo-Yo (5,753 loop-the-loops) and reveal the human race at its zaniest.

Somebody in Los Angeles balanced on one foot for 7 1/2 hours. Under "Band, One-Man" appears Werner Hirzel, who plays 40 instruments in a single tune. A lot of records involve bricks, pianos and eggs for some reason, and many more concern dancing. There are records for the slowest typing (Chinese characters) and the fastest psychiatrist (50 patients a day; he was arrested finally), from Joke Telling to Speech Listening, from Ironing and Needle Threading to Bed Pushing and Riding in Armor.

Footnote to the Spitting record: "Spitters who care about their image wear 12-inch boots so practice spits can be measured without a tape."

A somewhat hair-rasing caveat is attached to the section on Gastronomic Records, to the effect that Guinness will not list anything involving more than two liters of beer, no spirits at all, and no "live ants, quantities or chewing gum or marshmallows, or raw eggs in shells." They do run records for consuming everything from baked beans to tortillas.

Most of these records date from the early 1970s, when the book hit the younger generation of Americans with such force that one writer, condemning our TV-watching habits, noted the decay of reading and the rise of "nonbooks" like especially the Guinness Book.

In fact, Guinness has had to take steps to avoid becoming the cause of hundreds of artificial fads. All it takes is somebody idly swinging a stick at a dandelion to say, "Hey, I wonder how many times I can hit this without breaking it." And the very next thought: "Hey, the Guinness Book of Records."

Sean Sullivan, assistant editor of the American edition, which comes out in hardback (Sterling) every October and in paperback (Bantam) in April, said one rule of thumb is that an event must have international significance or interest and it must be approved by the home staff in england.

"It comes in spurts," he said. "Suddenly we'll get 150 phone calls from people doing volleyball marathons. There's no season to it, though."

What he meant was a period that Life magazine used to call the silly season, in early spring, back in the '40s when college students would swallow goldfish or crowd into phone booths or hold campus Walpurgisnachts --they called them riots, but Kent State they weren't -- and usually some of them would get their pictures in Life. Guinness has inherited the screwball celebrity, apparently.

Sullivan wouldn't talk about failed stunts. "We don't want anybody to know about the ones that don't make it. People would be all over us. It's bad enough as it is: somebody on TV claims to be the world record holder in some nonevent that he says is in the book -- and it's not in the book at all. So then we get a flood of challengers."

Once on a TV show someone said he was beating the world mark in coin snatching, set by an Englishman who in 1973 caught 39 coins in the air after flipping them off his forearm. The trouble was, the usurper used dimes; the real record was made with heavy British coins as big as half-dollars.

"Now we're getting a lot of queries about skateboarding marathons. But they probably won't get into the book."

Hula hooping, however, did.

Staffers at headquarters outside London confirmed by phone that "our general policy is to include only existing records." Vast files are kept, though, of fringe activities, and it is possible for a new event to force itself upon the dietors' attention.

A whole page of the book is devoted to careful instructions about filing claims. Anything qualified in some way, by age, day of week or area, for example, is out. Adult independent witnesses, not family or friends, are required to sign a logbook and the book must be notarized. Notarized statements from two responsible persons in the community also are required.

The record also needs to be corroborated by newspaper clippings or radio or TV coverage records, hence the rush to fame in city rooms across America.

Of course, the stunts cover only a tiny part of this remarkable, ironically urbane book. It is hard to think of another single volume that goes so far toward defining the physical world we live in, the phenomena of the human body and the animal and plant worlds, the limits of endurance and size, achievements in science, business, sports the arts and was the dimensions of our univerise down to the microbes.

Just the thing to give to a Martian.