Cal. Probate Code § 6382

(a) The will shall be made in writing. It need not be written by the testator himself or herself. It may be written in any language, by hand or by any other means. (b) The testator shall declare in the presence of two witnesses and of a person authorized to act in connection with international wills that the document is the testator’s will and that the testator knows the contents thereof. The testator need not inform the witnesses, or the authorized person, of the contents of the will. (c) In the presence of the witnesses, and of the authorized person, the testator shall sign the will or, if the testator has previously signed it, shall acknowledge his or her signature. (d) If the testator is unable to sign, the absence of the testator’s signature does not affect the validity of the international will if the testator indicates the reason for his or her inability to sign and the authorized person makes note thereof on the will. In that case, it is permissible for any other person present, including the authorized person or one of the witnesses, at the direction of the testator, to sign the testator’s name for the testator if the authorized person makes note of this also on the will, but it is not required that any person sign the testator’s name for the testator. (e) The witnesses and the authorized person shall there and then attest the will by signing in the presence of the testator.