California Code, Education Code - EDC § 56021.1

(a) The parent or guardian has been fully informed of all information relevant to the activity for which consent is sought, in his or her native language, or other mode of communication.

(b) The parent or guardian understands and agrees in writing to the carrying out of the activity for which his or her consent is sought; and the consent describes that activity and lists the records, if any, that will be released and to whom.

(c) The parent or guardian understands that the granting of consent is voluntary on the part of the parent or guardian and may be revoked at any time. If a parent or guardian revokes consent, that revocation is not retroactive to negate an action that has occurred after the consent was given and before the consent was revoked.A public agency is not required to amend the education records of a child to remove any reference to the child's receipt of special education and services if the child's parent or guardian submits a written revocation of consent after the initial provision of special education and related services to the child.