Cal. Rev. & Tax. Code § 6422.1
The board may provide for exemption certificates and other tax clearance certificates to be issued by it or by retailers selling vehicles as defined in Article 1 (commencing with Section 6271) of Chapter 3.5, commercial coaches as defined in Section 18001.8 of the Health and Safety Code or mobilehomes as defined by Section 18008 of the Health and Safety Code. The certificates shall be used to allow a completion of registration of a vehicle by the Department of Motor Vehicles or a commercial coach or mobilehome by the Department of Housing and Community Development. The certificates may indicate that the board finds that no use tax is due or is likely to become due with respect to the storage, use, or other consumption of the vehicle, commercial coach, or mobilehome, or that the tax has been paid or is to be paid in a manner not requiring the withholding of a registration or transfer of registration. The certificates shall be in such form as the board may prescribe and shall be executed, issued and accepted for clearance of registration on such conditions as the board may prescribe. The issuance, alteration, forgery, or use of any such certificate in a manner contrary to the requirements of the board constitutes a misdemeanor.
Ca. Rev. and Tax. Code § 6422.1