Cal. Educ. Code § 44661.5

When developing and adopting objective evaluation and assessment guidelines pursuant to Section 44660, a school district may, by mutual agreement between the exclusive representative of the certificated employees of the school district and the governing board of the school district, include any objective standards from the National Board for Professional Teaching Standards or any objective standards from the California Standards for the Teaching Profession if the standards to be included are consistent with this article. If the certificated employees of the school district do not have an exclusive representative, the school district may adopt objective evaluation and assessment guidelines consistent with this section.