The Expedition 10 Mission decal uses simple symbolism to describe the mission. The large Roman numeral X; formed by the American and Russian flags, symbolizes the joint nature of this mission, as well as the fact that this flight is the 10th mission to stay on the International Space Station (ISS). The current configuration of the ISS is next to the name of the ISS Commander, while the Soyuz vehicle is placed next to the name of the Soyuz Commander. The single star and black background signify this is a space mission.
Details from the rear of the decal.