Update, May 23, 2018: The NFL has unveiled a new rule requiring players to "stand and show respect for the flag and the Anthem." This story, originally published in September 2017, reflects the rules and policies in effect at that time, when President Donald Trump began criticizing kneeling players.

If you've been on social media in the last few days, it's been impossible to avoid discussion about national anthem protests at NFL and other sporting events.

So it's likely you've seen a meme like this floating around:

The meme claims that page 62-63 of the "NFL rule book" dictates that during the national anthem, players must stand, face the flag, hold their helmet in their left hand and refrain from talking. The meme claims that failure to follow this policy can result in fines, suspensions or forfeiture of draft picks.

So, is it true?

Technically, yes. But it's not in the "NFL rule book."

While this language does not appear in the 2017 Official Playing Rules of the National Football League, which is available in its entirety online, it is a part of the game operations manual, which is distributed to all 32 teams, according to NFL spokesperson Brian McCarthy.

McCarthy said that the policy has been in place for several years, pre-dating protests that began during the 2016 season.

"It’s policy, it’s not a rule. I think where people are getting confused is, rules, that’s like holding or defensive pass interference, that’s a rule. This is policy," McCarthy said.

McCarthy confirmed that the league will not assess penalties to players who either did not take the field for the anthem or who protested.

In the publicly available 2017 Official Playing Rules of the National Football League, the word "anthem" is not mentioned.

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The only section that could potentially apply to anthem protests in the rules (not to be confused with the policies) comes under the section on player equipment, uniforms and player appearance. Rule 5, Section 4, Article 8 (found on page 23), deals with "personal messages." Here's how that rule begins:

"Throughout the period on game-day that a player is visible to the stadium and television audience (including in pregame warm-ups, in the bench area, and during postgame interviews in the locker room or on the field), players are prohibited from wearing, displaying, or otherwise conveying personal messages either in writing or illustration, unless such message has been approved in advance by the League office. Items to celebrate anniversaries or memorable events, or to honor or commemorate individuals, such as helmet decals, and arm bands and jersey patches on players’ uniforms, are prohibited unless approved in advance by the League office."

While this does address "conveying personal messages," the entirety of the rule is related to uniforms and wearing items that convey personal or political messages. It does not at any point mention behavior that conveys personal or political messages, outside of prohibiting players from "orally promoting equipment, apparel, or other items that carry commercial names or logos/identifications of companies," unless approved in advance.

Allison Carter is social media editor at IndyStar. Follow her on Twitter @AllisonLCarter.