California Code, Revenue and Taxation Code - RTC § 18902

(a) An individual may designate on the tax return that a contribution in excess of the tax liability, if any, be made to the Rape Kit Backlog Voluntary Tax Contribution Fund, which is established by Section 18903. That designation is to be used as a voluntary contribution on the tax return.

(b) The contributions shall be in full dollar amounts and may be made individually by each signatory on a joint return.

(c) A designation shall be made for any taxable year on the initial return for that taxable year and once made is irrevocable. If payments and credits reported on the return, together with any other credits associated with the taxpayer's account, do not exceed the taxpayer's liability, the return shall be treated as though no designation has been made.

(d) The Franchise Tax Board shall revise the form of the return to include a space labeled the “Rape Kit Backlog Voluntary Tax Contribution Fund” to allow for the designation permitted. The form shall also include in the instructions information that the contribution may be in the amount of one dollar ($1) or more and that the contribution shall be used for DNA testing in the processing of rape kits.

(e) A deduction shall be allowed under Article 6 (commencing with Section 17201) of Chapter 3 of Part 10 for any contribution made pursuant to subdivision (a).