California Code, Revenue and Taxation Code - RTC § 6370.5

(a) This section applies to nonprofit associations and equivalent organizations performing auxiliary services to any city or county museum in the state, which are authorized to operate within the museum by the governing authority of the museum and have held an annual rummage sale for at least five consecutive years immediately preceding the sale referred to in subdivision (b).

(b) An organization described in subdivision (a) is a consumer of, and shall not be considered a retailer within the provisions of this part with respect to, tangible personal property which it sells at an annual rummage sale; provided, the profits are used exclusively in furtherance of the purposes of the organization.

(c) This section shall not be applicable to the state or any of its political subdivisions.