(a) a written request for disclosure in physical or electronic form;
(b) a copy of the power of attorney expressly granting the agent authority over the content of electronic communications of the principal;
(c) an affidavit in which the affiant attests that the copy is an accurate copy of the original power of attorney and that, to the best of the affiant's knowledge, the power remains in effect; and
(d) if requested by the custodian:
(1) a number, username, address, or other unique subscriber or account identifier assigned by the custodian to identify the principal's account; or
(2) evidence linking the account to the principal.