Definitions for "Signboard"
A board, placed on or before a shop, office, etc., on which ssome notice is given, as the name of a firm, of a business, or the like.
structure displaying a board on which advertisements can be posted; "the highway was lined with signboards"
A signboard is a board carrying a sign or notice, usually used for advertising of products, events, houses for sale or let, etc. They are also used for cautionary or educational purposes.
Information stenciled on side of car pertaining to empty car movement instructions.
Keywords:  pit, road, tell, driver, him
The sign held up when the driver comes down pit road to tell him where his pit space is located.