It’s been a tradition – and official Olympic policy – since the inaugural Parade of Nations at the 1908 Olympics in London. Each nation’s flag bearer should dip their banner when passing the heads of state and dignitaries from the host nation, as a sign of goodwill and respect. By all accounts, American flag bearer Michael Phelps did not do that this year in Rio, which comes as no surprise. Phelps was simply upholding a longstanding American tradition when it comes to flag dipping.

No one why knows for certain, but the story goes that American flag bearer Ralph Rose – one of many Irish-Americans on the 1908 Olympic team – simply wanted to make a point.  

"They were incensed, and had been for years, that Ireland was incorporated into Great Britain’s Olympic team and that Irish athlete’s had to march behind the Union Jack," said Mark Dyreson, a professor of history and kinesiology at Penn State University.

Dyreson suspects there was also a little of the “Spirit of ‘76” on Rose’s mind as he led the Americans through White City Stadium in London. 

"As the nations marched past the royal box, Ralph Rose did not dip the flag," he explained.

And so the precedent was set, albeit not decisively. For the next few decades, at some games we dipped the flag, and at others we didn’t. But it was in 1936, with the Olympics being held in Hitler’s Germany, that United State Olympic Committee first took an official position on the matter.

"And it is a political protest," said Dyreson. "They intentionally decided not to dip the flag as a sign of American unease – I guess, to put it mildly – with the Nazi regime and the Nazi leader."

We haven’t dipped our flag at an Olympics since.

In the 1940s, the policy became federal law, adopted as part of the official United States Flag Code, which states explicitly, “the flag should not be dipped to any person or thing.”

"The flag represents a living country and itself is considered a living thing," explained Mike Buss, a flag expert for The American Legion.

The comprehensive code stipulates when the flag should be flown to where and how it should be displayed. It details everything from where a flag should be exhibited on a motor vehicle (fixed firmly to the chassis or clamped to the right fender) to the fact that the flag should always be "hoisted briskly and lowered ceremoniously."

It also says the flag should never be worn as apparel, which caught my eye given all the clothes bearing the stars and stripes at the Olympics. Buss set me straight.

"As long as the article of clothing is not made from an actual United States flag, we have no problem with it," he said. "It might be red white and blue, have stars and stripes and look a heck of a lot like a flag – that’s an image of the flag that’s not the flag."

And while we adhere to the flag code strictly during the Opening Ceremonies, Buss says it is regularly violated at the Olympics.

"When an athlete – in the heat of competition – wins, and the next thing you know they’re draped in the flag behind them or whatever; that’s considered a breach of flag etiquette," he explained. 

There was a time when breaching the flag code was a punishable civil offense, but those days are long gone.

"When the Supreme court decreed that burning the flag is considered free speech, any portion of the law that indicated that there was a penalty, well that all got struck.

Freedom of individual expression has led to some close flag dipping calls. In 1968, gold medal hammer thrower and Somerville native Hal Connolly said he would dip if he was elected flag bearer, but in the end he wasn’t. Four years later his wife Olga, a discus thrower, was, and many thought that she would dip.

"And, in fact, when she marches by the Chancellor’s box in Germany in 1972, she raises the flag even higher," said Dyreson.

In the early years, Dyreson says that America’s refusal to dip Old Glory rankled plenty – from the International Olympic Committee to competitors from across the globe.

"[There were] claims of American arrogance, of American lack-of-manners, said Dyreson. "'Why won’t they dip? Oh, it’s the over-nationalistic Americans.'”

But when the Soviet Union joined the Olympic movement in the 1950s, they also instituted a non-dipping policy. That set off something of a flag-dipping-arms-race that culminated in the 1992 Winter Games in Albertville, France where 60 of the 64 countries who participated in the Parade of Nations chose not to dip their flags. 

Officially, the IOC continues to recommend that nations dip their flag out of respect to the host nation. Dyreson says that, today, some do, and some don’t in various years for a variety of reasons.

And while the Olympics may be about sportsmanship and goodwill; politics, power, and national pride are unavoidable aspects of any international event. In fact, Dyreson says, that’s – at least in part – why we watch.

"Were you to take out national flags, and national anthems, and national uniforms, no one would watch the Olympics," he said. "An Olympics without nationalism is probably not a very exciting one."

So go ahead, break out your flag and cheer on your nation. Just remember, if you’re thinking about getting creative with it, you might just want to check the flag code first.