"Reggie!" "Reggie!" "Reggie!" chanted the crowd after the public address announcer said "Welcome to Yankee-Stadium-for-today." The day's stadium was a hotel dining room, the crowd was on tape and the cheering was just part of a dandy launching for Reggie Jackson's new candy bar.

The slugger, who joked when he played for the Oakland A's that they would name a candy bar for him if he played in New York, was the centerpiece in a candy-Yankee promotion for the orange paper-wrapped square of "chocolaty-covered caramel and peanuts" that proves Jackson a prophet.

The Dixieland quartet dressed in Yankee pinstripes and the young women wearing pinstripes with Jackson's 44 on their backs as they passed out free samples and autographed framed candy wrappers, are part of a proud tradition of what candy-makers Standard Brands Confectionery call "product exploitation" and others call hype.

Launching a candy bar is not done without fanfare.

Thousands of candy bars have been dropped from planes on unsuspecting urban centers, Adm. Richard Byrd's expedition to the South Pole was persuaded to take along candy bars and there have been speedboat races, a 26-man air circus and 100-pound candy bars used to attract candy eater's attention and win their loyalty.

And they are very loyal. Ronald Cappadocia, who helped Jackson pull the golden rope that dropped the blue curtain and reveal a blowup of a "Reggie!" (the exclamation point is from the crowd's chant) bar, remarked that candy display counters are pretty much the same today as they were 20 years ago.

Cappadocia, Standard Brands Sales Company's president, said the "Reggie!" has the potential to do as well as his company's two long-time successes, Baby Ruth and Butterfingers, which have about 8 percent of the market between them.

Each percentage point is worth about $15 million in annual sales, Cappadocia said.

The new candy bar will be a moneymaker if it only gets 2 percent, he said.

And what happens if Jackson hits .180 next year?

"Well," Cappadocia replied, "the concept is mainly based on one moment in time . . . and on the man, of course."

The moment(s) are Jackson's three home runs in the last game of the 1977 World Series. The television commercials promoting "Reggie!" show him taking those three home-run swings and then end with him bitting into a "Reggie!" and saying: "Reggie!, You taste pretty good."

Jackson's three home runs in one series game is a feat only achieved earlier by Babe Ruth, who did it twice. And Babe Ruth, according to Standard Brands executives, never had a candy bar named after him.

The Baby Ruth, Standard Brands told yesterday's luncheon at the Plaza Hotel, was named for President Grover Cleveland's daughter.

It is a safe bet that Jackson's contract with Standard Brands, which runs 10 years, pays him more than Ruth Cleveland got for her candy bar, but Cappadocia declines to reveal its terms.

Like many star professional athletes' contracts, it appears to have bonus clauses. "He's got a stake in how well the bar does just as we do," Cappadocia said.

His stake is in 2 ounces containing: "Sugar, peanuts, corn syrup, hydrogenated vegetable oil, nonfat dry milk, chocolate liquor, dairy whey, whole milk solids, cocos, brown sugar, salt, lecithin (emulsifier), artificial flavore."

It is chewy and sweet and sets off the appropriate alarm bells about teeth in the conditioned mind. The taste is pleasant but not unfamiliar.

With Yankee-owner George Steinbrenner looking on approvingly, Jackson predicted the Yankees are headed for another American League title this year.

He said he wished he was as sure of the 25-cents-for-2-ounce-candy bar success as he is of the Yankees.

After his speech, Jackson went off to do a series of television and radio interviews under the watchful eye of Standard Brands.

"I went to high school with Reggie," said Bill Goff, who was hoping for a chance to renew their acquaintanceship. "His yearbook prediction said, 'major league baseball,' he knew," Goff said.

Over to one side, Lt. I. Ballard stood guarding the baseball that Reggie Jackson hit for his historic third home run. Ballard kept a close eye on the ball in its Plexiglas case.

Does the ball belong to Jackson?

"Oh, no, to Standard Brands," he said.