Cal. R. 8.254
If a party learns of significant new authority, including new legislation, that was not available in time to be included in the last brief that the party filed or could have filed, the party may inform the Court of Appeal of this authority by letter.
The letter may provide only a citation to the new authority and identify, by citation to a page or pages in a brief on file, the issue on appeal to which the new authority is relevant. No argument or other discussion of the authority is permitted in the letter.
The letter must be served and filed before the court files its opinion and as soon as possible after the party learns of the new authority. If the letter is served and filed after oral argument is heard, it may address only new authority that was not available in time to be addressed at oral argument.
Cal. R. Ct. 8.254
Advisory Committee Comment
This rule does not preclude a party from asking the presiding justice for permission to file supplemental briefing under rule 8.200(a)(4). A letter filed under this rule does not change the date of submission under rule 8.256.