what do you expect them to call you?Chinese? Chinese from China? Locals are Chinese as well. When it comes to a point differentiation is needed, PRC is a convenient acronym name. All been said, there's nothing wrong with PRC and you should be proud of the identity PRC entails.

nationality是国籍，应该填CHINA吧，RACE才是CHINESE（华人）？

国家可以叫ROS....人可以叫ROSean吗? American叫United States of American吗?

ps.Helsinki airport code is HEL...