ABC News' Sarah Parnass reports:

The Super Bowl: it's a great American tradition, but did spectators and sportsmen skip out on another American tradition right before kick off?

As Kelly Clarkson sang the national anthem at a packed Lucas Oil Stadium in Indianapolis Sunday night, the camera flashed from her face to fans and football players - many of whom did not have their hands over their hearts.

Though New York Giants Coach Tom Coughlin held his hat there, some of his players - including Brandon Jacobs and Derrick Martin - appeared to have their arms at their sides.

The Independence Hall Association says the Flag Code, adopted first in 1923, requires those who are not members of the Armed Forces or veterans to face the flag and stand with a hand over their heart. Men in these crowds are told to remove hats or other headwear with their right hands and place them over their left shoulders. eHow.com - a less formal guide - also recommends dropping your nachos and putting out your cigarette.

New England Patriots wide receiver Deion Branch wore no helmet during Clarkson's rendition last night, but he did wear a piece of material over his head. Fans and staff milling in the background could also be seen in casual stances and sporting hats. How much does it matter that these people shirked the traditional pose?

If you asked Mitt Romney, he'd likely rank it as a significant stumble. At stump speeches across the country, the GOP presidential front-runner has praised America's standard for celebrating the anthem, often botching historical information in the process, the Washington Post reports .

The Flag Code leaves out a punishment for violating its requirements, so there are no legal consequences for those who break its rules. And according to the National Anthem Project, improper etiquette might not be the worst "Star Spangled" faux pas Americans make.

The project, hosted by the National Association for Music Education in 2007, reported many people in the country did not know the words to the anthem, and some didn't even realize it had more than one verse. In fact, the lyrics Francis Scott Key wrote on the back of a letter in 1814 include four verses.

Elizabeth Lasko, assistant executive director at the NAME's Center for Members & Constituency Relations, said music educators across the nation are more concerned with Americans learning and singing the song than they are with etiquette.

"Our position on the national anthem has always been that people should sing it together," Lasko said. This is in line with the 1942 National Anthem Committee , which wrote, "Since the message of the music is greatly heightened by the test, it is of paramount importance that emphasis be placed upon the singing of the National Anthem."

Problems arise when the anthem is performed "as a solo showcase for outstanding singers," Lasko said, because it scares away the everyday citizen.

"Everybody can sing it," Lasko said. "You just have to learn it."

President Obama notoriously neglected to put his hand over his heart during "The Star Spangled Banner" leading up to the 2008 elections.

Obama's defense of his flag-saluting flub fell in line with Lasko's recommendations. At a town hall meeting after the incident, Obama told the crowd , "I was taught by my grandfather that you put your hand over your heart during the pledge, but during "The Star Spangled Banner," you sing!"