From the New York Times
The uniforms here create a vibrant backdrop, with each athlete becoming a moving billboard for his or her country. They form a seemingly haphazard collection — some country names are written in English, some in other languages. But they are actually part of a grand design, regulated by a phone-book-sized set of International Olympic Committee rules.
Because country names on the front must be written in the Latin alphabet, countries like China compensate by using Chinese characters on the back. Flags and sponsor logos must be in a certain place and a certain size. The colors are regulated.