California Codes, Code of Civil Procedure - CCP, Part 2 — Of Civil Actions, Title 8.5 — Uniform Foreign-money Claims Act, Section 676.6
(a) A person may assert a claim in a specified foreign money. If a foreign-money claim is not asserted, the claimant makes the claim in United States dollars.
(b) An opposing party may allege and prove that a claim, in whole or in part, is in a different money than that asserted by the claimant.
(c) A person may assert a defense, setoff, recoupment, or counterclaim in any money without regard to the money of other claims.
(d) The determination of the proper money of the claim is a question of law.
Notes
Allows a claimant to assert a claim in specified foreign money, with an unasserted foreign-money claim treated as a United States dollar claim. An opponent may prove a different proper money, defenses and counterclaims may use any money regardless of other claims, and determining the proper money is a question of law.
Use as reference
Lexinter.net | California Code, Code of Civil Procedure - CCP § 676.6 | https://laws.lexinter.net/codes/california/code-of-civil-procedure/part-2/title-8-5/section-676-6