If you are displaying an American flag today, good for you. It’s Flag Day in the United States, after all. But still, you might be doing it wrong — and veterans are likely to have noticed.

While there are no legal penalties for running afoul of the U.S. Flag Code, many veterans do frequently spot violations, said Joe Plenzler, a spokesman for the American Legion, a veterans organization.

Following the code is entirely voluntary, but “it’s a significant emotional issue for many of our veterans,” he said.

To be sure, mistakes are often made with the best of intentions or without knowledge of specific details in the extensive code.

“I think it’s just because they don’t know any better, and that’s where we come in as veterans to help them understand,” said Lynn Rolf, programs director at Veterans of Foreign Wars.

If you want to avoid offending someone, here are some of the most frequent mistakes people make with their flags.

IF IT’S RAGGED, GET RID OF IT

If a flag is dirty, tattered or faded, don’t bother flying it.

“In their patriotism, people many times forget that displaying a soiled flag is not the way to go about it,” Plenzler said. “We like to encourage people to buy new flags, and make sure the flags they have are in presentable condition.”

‘PREFERABLY BY BURNING’

Don’t just throw it in the garbage. The code says: “The flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning.”

The code offers no specific guidance on how to burn it. A 2008 report by the Congressional Research Service wrote that “any procedure which is in good taste and shows no disrespect to the flag would be appropriate.”

Many American Legion posts hold public ceremonies to dispose of old flags on Flag Day. Rolf said most VFW chapters will accept flags, and will often work with local Scout troops to properly dispose of them.

If you do it yourself, the legion suggests burning it in private, so others don’t confuse your action with a political protest.

That said, it should be noted that burning the flag in protest, while offensive to many people, remains constitutionally protected under a Supreme Court ruling in 1989. From time to time, Congress has tried and failed to reverse that ruling.

TOUCHING THE GROUND

One thing to note: Some people mistakenly believe a flag must be burned if it touches the ground. That’s a myth that pervades even active service members, Plenzler said.

You should try to avoid letting the flag touch the ground, but it can still be flown if it remains in good condition, he said.

FLYING AT NIGHT

If you do so, it should be well-lighted.

According to the code: “It is the universal custom to display the flag only from sunrise to sunset on buildings and on stationary flag staffs in the open. However, when a patriotic effect is desired, the flag may be displayed twenty-four hours a day if properly illuminated during the hours of darkness.”

The American Legion defines “proper illumination” as a light specifically placed to light the flag, or bright enough so the flag is “recognizable by the casual observer.”

FLAG SHIRTS AND HATS

The code states: “The flag should never be used as wearing apparel, bedding, or drapery. It should never be festooned, drawn back, nor up, in folds, but always allowed to fall free.”

There’s some debate among veterans about how disrespectful it is to wear clothing with a motif based on the flag.

You wouldn’t want to cut up an actual flag to fashion a shirt, but Rolf said he considered items based on the flag to be welcomed expressions of patriotism.

“We love people showing pride in our country, and right now I’ve got stars and stripes socks on,” Rolf said.

That said, you should be aware some veterans disagree and may tell you so, he said.

A similar logic applies to items designed like the flag, including beer cans or napkins, for your patriotic backyard barbecue.

According to the code: “The flag should never be used for advertising purposes in any manner whatsoever. It should not be embroidered on such articles as cushions or handkerchiefs and the like, printed or otherwise impressed on paper napkin or boxes or anything that is designed for temporary use and discard. Advertising signs should not be fastened to a staff or halyard from which the flag is flown.”

That said, maybe don’t buy a doormat that would require people to step on wipe their feet on the flag. (Lowe’s, a home improvement chain, found itself in a stir in 2012 when it sold a doormat that included elements of the flag.)

SO WHAT IS FLAG DAY?

Flag Day celebrates the anniversary of June 14, 1777, when Congress established the first design of the American flag with 13 stars and stripes.

The day was celebrated for decades in many parts of the country before President Harry Truman and Congress formally designated it and urged Americans to fly the flag at home. Some cities and towns celebrate with parades.

But do whatever you like. It’s a free country.