Rule 40 from the Olympic Charter describes a legal regulation for Olympic athletes. It was originally introduced to sanction ambush marketing strategies by companies that are not listed as official sponsors at the Olympic Games. For this reason, a "blackout period" was introduced. This period started nine days before the opening ceremony of the Olympic Games and ended three days after the closing ceremony. During this period, athletes were prohibited from promoting unofficial Olympic partners. At the Rio 2016 Olympics, the application of this rule led to numerous controversies. In case of the German Olympic Team, the German Federal Cartel Office determined that Rule 40 does not apply to German athletes.
As a result of the many controversies, the IOC adjusted Rule 40 for the Tokyo 2020 Games and introduced new requirements for sponsors who are not official Olympic partners.These partners will be allowed to continue their sponsorship engagement during the Olympic Games, provided it was completed at least 90 days before the Games. In addition, the sponsorship commitment may not be significantly increased during the Games. An example of how these principles affect sponsorship is explained in an official IOC information document