Every operator licensed under this Act shall, at all times, keep a sign posted in a conspicuous place over the main entrance to each warehouse, which sign shall clearly state the name of the person, firm, partnership, association or corporation operating said warehouse, and a statement that such warehouse is licensed and the number of such license; and each operator shall also display a like sign in a conspicuous place on all motor vans, trucks or other vehicles used by the operator to transport personal property to and from such warehouses.
240 ILCS 10/11