Which treaty pertains to protection of the Olympic Symbol?

Question

The first Olympic flag, presented to the IOC at the 1920 Olympics by the city of Antwerp, Belgium, was lost until 1977. Where had it been?

Answer 1

Nairobi Treaty

All States party to the Nairobi Treaty are under the obligation to protect the Olympic symbol – five interlaced rings – against use for commercial purposes (in advertisements, on goods, as a mark, etc.) without the authorization of the International Olympic Committee.