Cal. Bus. & Prof. Code § 21661

(a) As used in this article, the term “swap meet” includes a flea market or an open-air market and means an event at which two or more persons offer merchandise for sale or exchange and that meets one of the following conditions:
1. (1) A fee is charged for the privilege of offering or displaying merchandise for sale or exchange.
2. (2) A fee is charged to prospective buyers for parking or for admission to the area where merchandise is offered or displayed for sale or exchange.
3. (3) The event is held more than six times in any 12-month period.
(b) Notwithstanding subdivision (a), the term “swap meet,” as used in this article, includes a flea market or an open-air market and means an event, regardless of the number of persons offering or displaying personal property or the absence of fees, at which used personal property is offered or displayed for sale or exchange if the event is held more than six times in any 12-month period.
(c) The term “swap meet,” as used in this article, is interchangeable and applicable to “flea markets,” “indoor swap meets,” “open-air markets,” or other similar terms, regardless of whether these events are held either inside a building or outside in the open. The primary characteristic is that these activities involve a series of sales sufficient in number, scope, and character to constitute a regular course of business.
(d) “Operator,” as used in this article, means any person, partnership, organization or corporation that controls, manages, conducts or otherwise administers a swap meet.
(e) “Vendor,” as used in this article, means any person, partnership, organization or corporation who exchanges, sells, or offers for sale or exchange any merchandise at a swap meet. A swap meet vendor shall be classified according to the following categories:
1. (1) A “casual swap meet vendor” means a vendor who participates in a swap meet two times or less per year.
2. (2) A “regular swap meet vendor” means a vendor who participates in a swap meet three or more times per year.