At the Olympics in Rio de Janiero, athletes from around the world are posting tweets, photos and observations between training and competing.
Missing from their social media updates: any mention of companies that are not part of the exclusive club of official Olympic sponsors.
That’s because of Rule 40, a section of the Olympic Charter that bars such businesses from mentioning the Olympics or the athletes they sponsor in any way from July 27 to Aug. 24. Athletes are likewise not allowed to acknowledge their sponsors during that period.
The rule extends to social media, where banned words include the wholly expected (such as “Olympics,”...