» RELATED: Social media explodes after NFL ruling on national anthem

Throughout the 1880s, Cigrand spoke out about respecting the flag and what it means for patriotism. June 14, he said, was the flag’s birthday, the day the Continental Congress adopted the “Stars and Stripes.”

In 1886, the teacher-turned-dental student proposed an annual observance of the holiday in the Chicago Argus newspaper. The article was titled, “The Fourteenth of June.”

Cigrand would go on to become president of the American Flag Day Association and later, of the National Flag Day Society.

School celebrations in honor of Flag Day took off in June 1894. And though Cigrand’s Stony Hill High School is now a historical site, it wasn’t until 1949 that President Truman’s signature made Flag Day’s permanent observance the law of the land.

In recent years, the country has watched as several NFL players and owners throughout the league either kneeled or locked arms during national anthem performances in solidarity against President Trump’s call to fire protesting players.

Last May, NFL owners announced the unanimous decision requiring players and personnel to stand during the anthem if they are on the field. Failure to do so would result in fines.

There is an option for players to remain in the locker room.

According to ESPN, the NFL Players Association said it would review the policy and may challenge it if it violates the collective bargaining agreement.

» RELATED: Olympian John Carlos, who raised a fist in 1968" on taking a knee

To those who choose to kneel or lock arms during the “Star-Spangled Banner,” the act protests perceived social injustices against African-Americans, such as the incidents of unarmed black people being shot by police.

To Trump and NFL commissioner Roger Goodell, the act shows a lack of patriotism and disrespect to the American flag.

According to Title 36 (section 171) of the United States Code, “all present except those in uniform should stand at attention facing the flag with the right hand over the heart.” There is no legal penalty for not standing or choosing to kneel, however.

The U.S. flag code's "Respect for Flag" section (Title 4, Chapter 1, Section 8) lists the dos and don'ts for respecting the American flag−neither kneeling nor standing during the national anthem is included under the section.

It is, however, considered a conduct violation.

But what’s included on the list of flag no-no’s may surprise you.

» RELATED: Roger Goodell's statement on national anthem policy

Here are seven ways people can and do disrespect the flag, according to U.S. flag code.

An American soccer fan wears his American flag socks as he waits for his team to play against Ghana at the FIFA World Cup Fan Fest on Copacabana beach on June 16, 2014 in Rio de Janeiro, Brazil. Credit: Joe Raedle Credit: Joe Raedle

1. Wearing the flag

“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.”

2. Carrying the flag flat or horizontally

“The flag should never be carried flat or horizontally, but always aloft and free.”

3. Using the flag as a marketing tool

“The flag should never be used for advertising purposes in any manner whatsoever.”

4. Embroidering the flag on cushions

“It should not be embroidered on such articles as cushions or handkerchiefs and the like.”

5. Printing the flag on paper products or anything made to be discarded after using (like paper plates)

It should not be “...printed or otherwise impressed on paper napkins or boxes or anything that is designed for temporary use and discard.”

6. Letting the flag touch anything under it

“The flag should never touch anything beneath it, such as the ground, the floor, water, or merchandise.”

7. Using the flag to decoratively (or not) cover the ceiling

“The flag should never be used as a covering for a ceiling.”

Note that there are no provisions in the code for enforcement nor penalties. Instead, the code acts as a guide.

You cannot be forced to stand for the national anthem nor can you go to jail for any of the aforementioned modes of disrespect.

Courts are likely to uphold such conduct is protected by the First Amendment.

Read the U.S. Code "Respect for flag" section here.