(a) The board may adopt reasonably necessary rules and regulations to effect the classification of contractors in a manner consistent with established usage and procedure as found in the construction business, and may limit the field and scope of the operations of a licensed contractor to those in which he or she is classified and qualified to engage, as defined by Sections 7055, 7056, 7057, and 7058. A licensee may make application for classification and be classified in more than one classification if the licensee meets the qualifications prescribed by the board for such additional classification or classifications. The application shall be in a form as prescribed by the registrar and shall be accompanied by the application fee fixed by this chapter. No license fee shall be charged for an additional classification or classifications. Nothing contained in this section shall prohibit a specialty contractor from taking and executing a contract involving the use of two or more crafts or trades, if the performance of the work in the crafts or trades, other than in which he or she is licensed, is incidental and supplemental to the performance of the work in the craft for which the specialty contractor is licensed.