Cal. Evid. Code § 1420 : CALIFORNIA EVIDENCE CODE — WRITINGS — AUTHENTICATION AND PROOF OF WRITINGS — MEANS OF AUTHENTICATING AND PROVING WRITINGS — Response to communications TEXT PDF A writing may be authenticated by evidence that the writing was received in response to a communication sent to the person who is claimed by the proponent of the evidence to be the author of the writing. Ca. Evid. Code § 1420 Enacted by Stats. 1965, Ch. 299.