California Code, Civil Code - CIV § 798.72

(a) The management shall not charge a homeowner, an heir, joint tenant, or personal representative of the estate who gains ownership of a mobilehome in the mobilehome park through the death of the owner of the mobilehome who was a homeowner at the time of his or her death, or the agent of any such person a transfer or selling fee as a condition of a sale of his mobilehome within a park unless the management performs a service in the sale. The management shall not perform any such service in connection with the sale unless so requested, in writing, by the homeowner, an heir, joint tenant, or personal representative of the estate who gains ownership of a mobilehome in the mobilehome park through the death of the owner of the mobilehome who was a homeowner at the time of his or her death, or the agent of any such person.

(b) The management shall not charge a prospective homeowner or his or her agent, upon purchase of a mobilehome, a fee as a condition of approval for residency in a park unless the management performs a specific service in the sale. The management shall not impose a fee, other than for a credit check in accordance with subdivision (b) of Section 798.74, for an interview of a prospective homeowner.