Pope Francis received a stern message about Olympic marketing after tweeting a good luck message as the Games kicked off.
“Good luck to the athletes at #Rio2016! May you always be messengers of goodwill and true sporting spirit,” the pontiff tweeted on Friday.
His tweet received an automatic reply from a since-suspended account called Rule 40, telling the pope he was violating “Olympic guidelines.”
“.@Pontifex please refrain from using #Rio2016 protected terms," the response said. "As a global brand you are in violation of official Olympic guidelines."
The account was referencing the Olympic Charter’s Rule 40, which limits athletes, coaches and other participants from appearing in advertising and other marketing, including social media posts, without the IOC's permission. Participants are also forbidden from wearing clothing with logos of non-Olympic brands.
The International Olympic Committee has also cracked down on non-sponsoring brands that reference the Olympics by name or use Olympic logos in tweets or advertisement.
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But it did not appear such messages would violate the rule and was unclear who was behind the unverified account. The website Rule40.com , which houses a link to the Twitter account, appeared to have no official link to the Olympics. The account was designed to look official. It was later suspended from Twitter.
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A favela is seen overlooking the rowing on Day 1 of the Rio 2016 Olympic Games at the Lagoa Stadium on Aug. 6, 2016, in Rio de Janeiro, Brazil.
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Rio 2016 logo is displayed before the Men's Road Race on Day 1 of the Rio 2016 Olympic Games at the Fort Copacabana on Aug. 6, 2016, in Rio de Janeiro, Brazil.
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The IOC did not immediately return a request for comment about the Twitter account.
Still, the response to the pope's tweet and similar messages to others who used the hashtag #Rio2016 prompted outcry across social media.
Among the notable names warned were former Republican presidential candidate and Texas Sen. Ted Cruz , the Houston Texans , Republican presidential candidate Donald Trump and the White House .
Trump tweeted a photo of himself wishing Team USA "good luck," while the White House tweeted a video message from president and first lady.
There's a long list of words that advertisers can't use, ranging from obvious ones like "Olympics" to seemingly benign ones like "effort" or "performance," depending on context. The IOC says the rules are in place to protect its sponsors' investment and prevent "over commercialization."
The blackout period for the crackdown by the IOC covers just one month — from July 27 to Aug. 24 for the Rio Olympics — it's a crucial window for many brands because for many athletes, this is the only time they have the world's attention.