Any provision of this part that refers to the application of any portion of this part to a prior period (or which depends upon the application to a prior period of any portion of this part) shall, when appropriate and consistent with the purpose of that provision, be deemed to refer to (or depend upon the application of) the corresponding provision of Part 10 (commencing with Section 17001) or Part 11 (commencing with Section 23001) as was applicable to the prior period.
Ca. Rev. and Tax. Code § 18414