1. The areas marked A, B and C in the diagram indicate areas of the surface on the face of the triangle as follows:
A — Red reflectorised surface. Not more than a total of 15 square centimetres may be obscured by constructional components.
B — Red fluorescent surface.
C — May have either red reflectorised surface or a combination of both red reflectorised and red fluorescent surface. Not more than 10 square centimetres in each corner may be obscured by constructional components.