California Code, Education Code - EDC § 22325

(a) The system, at least annually, shall identify and provide resources on its website that interpret and clarify the applicability of creditable compensation and creditable service laws in this part and regulations promulgated pursuant to this part.  Resources identified by the system shall be relied upon and used for purposes of subdivision (c) until and unless such a resource is revoked or superseded by the system.

(b) New or different interpretations of law, including those that would modify the application of prior interpretations, that differ from the resources identified by the system pursuant to subdivision (a) shall not take effect until after notice is issued to employers and exclusive representatives and shall not be applied retroactively to compensation reported prior to that notice, unless a retroactive interpretation is the result of a state or federal law, an executive order of the Governor, or a final court order.

(c) For purposes of audits or any other actions by the system, employers are responsible for complying with the laws and regulations in effect at the time the compensation is reported, except when such laws or regulations are superseded by state or federal law, an executive order of the Governor, or final court order.  If the system later determines that compensation reported in accordance with the system's resources identified pursuant to this section has been reported in error, as a result of an error in those resources, the resulting overpayment to the individual member, former member, or beneficiary shall be deemed an error by the system and shall be recovered pursuant to paragraph (4) of subdivision (a) of Section 24616.2.