While different schools will have different equipment and uniforms, there are some common elements amongst them. Uniform varies from school to school, however advanced students will usually wear black, and lower level students will usually wear white or, if more advanced, grey. These colors are often, but not always, displayed on the students school t-shirt. While special elasticated "kung-fu trousers" are often worn for safety (preventing caught feet and toes when training), it is also common to see normal track/jogging bottoms worn by low level students. Each school will have different rules. Instructors in WingTsun always wear black uniforms, with advanced instructors being signified with red being stripes featured on the uniform trousers. Gold or Yellow highlights are often used to signify additional rank, though this convention is far from universal.