10. The purposes for which the holder of a trade licence who is a motor trader may use a vehicle (other than a vehicle to which paragraph 14 applies) on a public road by virtue of that licence are purposes which meet each of the following requirements—
(a)they are business purposes;
(b)they are paragraph 12 purposes; and
(c)they are purposes that do not include the conveyance of goods or burden of any description except specified loads.