California Code, Business and Professions Code - BPC § 6735.4

(a) All mechanical engineering plans, specifications, calculations, and reports (hereinafter referred to as “documents”) prepared by, or under the responsible charge of, a licensed mechanical engineer shall include his or her name and license number. Interim documents shall include a notation as to the intended purpose of the document, such as “preliminary,” “not for construction,” “for plan check only,” or “for review only.” All mechanical engineering plans and specifications that are permitted or that are to be released for construction shall bear the signature and seal or stamp of the licensee and the date of signing and sealing or stamping. All final mechanical engineering calculations and reports shall bear the signature and seal or stamp of the licensee and the date of signing and sealing or stamping. If mechanical engineering plans are required to be signed and sealed and have multiple sheets, the signature, seal or stamp, and date of signing and sealing or stamping shall appear on each sheet of the plans. If mechanical engineering specifications, calculations, and reports are required to be signed and sealed or stamped and have multiple pages, the signature, seal or stamp, and date of signing and sealing or stamping shall appear at a minimum on the title sheet, cover sheet, or signature sheet.

(b) Notwithstanding subdivision (a), a licensed mechanical engineer who signs mechanical engineering documents shall not be responsible for damage caused by subsequent changes to or uses of those documents, if the subsequent changes or uses, including changes or uses made by state or local governmental agencies, are not authorized or approved by the licensed mechanical engineer who originally signed the documents, provided that the engineering service rendered by the mechanical engineer who signed the documents was not also a proximate cause of the damage.