17 C.F.R. § 190.03
(2) Open commodity contracts carried in hedging accounts. To the extent reasonably practicable under the circumstances of the case, and following consultation with the Commission, the trustee may treat open commodity contracts of public customers identified on the books and records of the debtor as held in a futures account, foreign futures account, or cleared swaps account designated as a hedging account in the debtor's records, as specifically identifiable property of such customer.
(ii) If the trustee exercises such authority:
(B) (1) Where, in the judgment of the trustee, the books and records of the debtor reveal a clear preference by a relevant public customer with respect to transfer or liquidation of open commodity contracts, the trustee shall endeavor, to the extent reasonably practicable, to comply with that preference.
(2) Where, in the judgment of the trustee, the books and records of the debtor do not reveal a clear preference by a relevant public customer with respect to transfer or liquidation of open commodity contracts, the trustee will request the customer to provide written instructions whether to transfer or liquidate such open commodity contracts. Such notice must specify the manner for providing such instructions and the deadline by which the customer must provide instructions.
(C) Such notice must also inform the customer that:
(1) (Where instructions have been requested pursuant to paragraph (c)(2)(ii)(B)(2) of this section), if the customer does not provide instructions in the prescribed manner and by the prescribed deadline, the customer's open commodity contracts will not be treated as specifically identifiable property under this part;
(2) Any transfer of the open commodity contracts is subject to the terms for distribution contained in § 190.09(d)(2);
(3) Absent compliance with any terms imposed by the trustee or the court, the trustee may liquidate the open commodity contracts; and
(4) Providing (or having provided) instructions may not prevent the open commodity contracts from being liquidated.
(e) Proof of customer claim. The trustee shall request that customers provide, to the extent reasonably practicable, information sufficient to determine a customer's claim in accordance with the regulations contained in this part, including in the discretion of the trustee:
(3) The number of commodity contract accounts held by each claimant, and, for each such account:
(f) Proof of claim form. A template customer proof of claim form which may (but is not required to) be used by the trustee is set forth in appendix A to this part.