In New York, they'd like you to think of it as a sort of National Football League in the spring. Anyplace else, it's the World League. And it's back, with its shortened name, starting today.

"We're opening in an entirely different environment. We have some sort of track record now," said the league's chief operating officer, Joe Bailey.

It used to be called the World League of American Football, 10 teams that included three in Europe. But the success it met in Barcelona, Spain, Frankfurt and London was so surprising, that league officials felt the "American Football" tag was superfluous.

Play begins with two games today, with three completing the first weekend on Sunday, including the New York/New Jersey Knights, who play the league-champion Monarchs at London in a game that will be televised by ABC-TV at 4 P.M. (Eastern time).

Gone are the Monday night games. Gone, too, is the Raleigh-Durham team, a victim of inattention by fans. That franchise was replaced by the Ohio Glory. Both the USA cable network and ABC have returned to televise the games, which will now be shown on a regional basis.

Still, both networks signed a three-year deal that will enrich the league by a total of about $25 million a year.

Look closely, and the signs of an N.F.L. partnership are unmistakable (the established league is underwriting the operation). On World League stationery, the N.F.L. logo made its first appearance this week, albeit on the bottom of the page.

This was to be the great leap forward for N.F.L. player involvement in the new league. And the N.F.L. did assign 110 players to training camps. About two-thirds have made the World League teams.

"They're not the top guys, but they're the 40th or 41st guys, and that's not too bad," says Boomer Esiason, who is returning as an analyst for the USA network. He is getting his voice in shape for calling signals as the Bengals' quarterback.

"On the Knights, you've got Brian Holloway trying to make a comeback," he said of the former Patriots' star offensive lineman. "At least now you've got the semblance of professionalism." Slack at Quarterback

Their most important newcomer is a Houston Oiler quarterback who has never been in an N.F.L. game -- Reggie Slack. The former Auburn star spent two years practicing with the Oilers, though, and is familiar with the run-and-shoot offense, a trademark of the Mouse Davis-coached Knights.

"We're way ahead of where we were last year," says Slack. "Many of the receivers had never been in a run-and-shoot before."

The season will be 10 games long, followed by one weekend of semifinal playoffs, and then the World Bowl in Montreal on June 6. EXTRA POINTS

The league will experiment with two helmet cameras -- on offense and defense -- when USA televises games so that a player will always be on the field wearing the contraption. And quarterbacks will be employing some sort of microphone so that the linemen farthest from him can hear the signals. The N.F.L. is especially interested in this experiment that attempts to counteract crowd noise. . . . The league averaged about 26,000 fans a game in its first season, with that average bolstered because of larger European crowds.