California Business And Professions Code Section 5659

Each person licensed under this chapter shall sign, date, and seal or stamp using a seal or stamp described in this section, all plans, specifications, and other instruments of service therefor, prepared for others as evidence of the person`s responsibility for those documents. Failure to comply with this section constitutes a ground for disciplinary action. Each person licensed under this chapter shall use a seal or stamp of the design authorized by the board, bearing his or her name, license number, the legend licensed landscape architect, the legend State of California and a means of providing a signature, the renewal date of the license, and date of signing and sealing or stamping.