Just in time for Valentine's Day, Mayor Nutter and City Council President Darrell L. Clarke came to an agreement on the renovation of John F. Kennedy Plaza, better known to skateboarders, lunching office workers, tourists, and bridal parties as LOVE Park. There had been a fierce debate about its fate, but one thing had never been in dispute: The LOVE sculpture would stay.

After all, the sculpture - based on a distinctive, stacked composition created by Robert Indiana 50 years ago - is practically the unofficial logo of Philadelphia. Just about any array of four letters can be (and has been) arranged in a grid, one letter askew, to imply Philadelphia ties.

It's a rather odd attachment given that Philly has no unique claim to LOVE or to its creator. Our version is just one of dozens of LOVE sculptures around the globe.

Susan Miller Davis, a consultant and former director of public art for the Philadelphia Redevelopment Authority, suggests that the location of Philly's LOVE makes it so iconic.

"That particular site is what makes it special and local," she said. "It's a universal theme in a very beautiful, local environment."

That is serendipitous, given that, when LOVE was first installed here in 1976, it was just on loan. The city could not, or would not, pay the $45,000 price, so in 1978 Indiana took the sculpture back. But that year, civic leader F. Eugene Dixon Jr. cut a deal, paying $35,000 for the popular artwork's return.

Today, most of the best public art is site specific, Miller Davis said. "Otherwise, it's a derogatory term called, 'plop art': You plop it down, and there it is." But LOVE, plopped though it was in JFK Plaza, just fit.

It was also, conveniently, far more photogenic than other nearby artworks: Claes Oldenburg's Clothespin, or the game pieces scattered by the Philadelphia Municipal Building - never mind Allow Me, the umbrella-wielding man at 15th and Chestnut who is one in a series by J. Seward Johnson. (While Philly's version is mostly ignored and sometimes abused, his Portland, Ore.-dwelling twin just might be that city's LOVE: It's cited in guidebooks as a local icon and Portland's "most photographed man.")

In addition, through the 1960s and '70s, LOVE was taken up as an emblem for the free love, sexual revolution, and antiwar counterculture movements.

While Philly's love for LOVE has been unconditional, Indiana never copyrighted the work and has complained about the endless rip-offs. LOVE's ubiquity made him an outsider in the New York art world. The same year Dixon bought the sculpture, Indiana went into exile in Maine.

A major retrospective of his work at New York's Whitney Museum of American Art last fall was pointedly titled "Robert Indiana: Beyond Love."

"His work was so overwhelmed by this one piece that no one had any conception of the things that had come before LOVE, and the much more dark, critical aspect of his work," the show's curator, Barbara Haskell, said.

After all, love was just one of the words Indiana explored in his artwork. He also made graphic works around die, eat, and err - that he believed were, like love, central to the human condition.

Yet, she acknowledged, "The LOVE image has a resilience, which the Philadelphia experience, I think, reveals. It's an image that allows people to put all their own expectations of that concept into it. Despite being sort of bastardized in all these trinkets and coffee mugs and key chains, the actual sculpture has a real presence that continues to empower people."

Of course, one person's bastardization is another person's homage.

Mark Adams, who runs a T-shirt company called Hog Island Press, said that as a graphic designer living in South Philadelphia, "I had to at least take a swing at it." A shirt that reads, "Yous," in Indiana's classic composition is one of his best sellers. (Others have done the same with the words "jawn" and "doop," the former being slang and the latter a cheer for the Philadelphia Union soccer team.)

Meanwhile, South Philly Tap Room has arranged its initials into an Indiana-inspired logo. And John Baily, who runs a new food truck called Brotherly Grub, is counting on his own version of the design to serve as visual shorthand for "Philadelphia."

"Philly was just voted the best sandwich town in the country, so it will be beneficial when I go to other states," he said.

Somewhat ironically - given that, in Haskell's analysis, the diagonal, destabilized "O" in LOVE hints at love's precariousness - weddings may be the biggest appropriators.

Frank Class III, of Frank's Ice in Bensalem, carves 40 or 50 LOVE ice sculptures a year for such occasions.

Rachel King Birch of Havertown twisted the "O" in LOVE into a pretzel and put the design on a note card; it sells well in her Etsy store as a wedding save-the-date.

And Zoë Lukas, owner of Whipped Bakeshop in Fishtown, moves lots of LOVE cookies, cupcakes, and fondant wedding-cake toppers. "If they're from Philly, or love Philly, or are using Philly as a destination wedding, it seems to be a popular motif," she said.

Dion Trinidad, 22, from Northeast Philadelphia, grew up believing LOVE was a uniquely Philadelphia landmark. He was disappointed when he realized, a few years back, that it was one of many sculptures by Indiana, who conceived of "covering the world with love."

Recently, though, Trinidad embarked on a project called One Thousand in LOVE, with the goal of photographing 1,000 visitors to the park, and making a book. "Last week, I got a family from England," he said. "They asked me to take a picture with their iPad, and I ended up becoming friends with the guy. They were my first friends from England." LOVE, it turns out, can be a self-fulfilling prophecy.

Photographer Bob Bruhin has spent as much time in LOVE Park as anyone. Since June 2012, he's been at work on a project called "LOVE in the Afternoon," online at afternoon-love.com. He takes up to 500 photos each month in the park: of tourists, other photographers, passersby, and the men who hang out near the statue, charging to take tourists' pictures.

"Shooting [LOVE] over and over has made me love it more," he said.

Turns out, the feeling is mutual. Indiana's agent, Marc Salama-Caro, said Indiana has been to LOVE Park and appreciates Philly's affection. "Mr. Indiana values LOVE as his most iconic work and is proud that it is embraced by the public, in Philadelphia as elsewhere."

LOVE Park, Bruhin said, is like no other place in the city. He has a request for its renovation: "You get people from all different parts of the city, all over the world, all mingling and bumping into each other. Whatever happens here, they need to preserve and enhance that."