c. Size of Patterns. Sides of the checkerboard
pattern should measure not less than 5 feet (1.5m) or
more than 20 feet (6m) and should be as nearly
square as possible. However, if it is impractical
because of the size or shape of a structure, the
patterns may have sides less than 5 feet (1.5m).
When possible, corner surfaces should be colored
orange.