19 C.F.R. § 10.206
(d) Cost or value of materials—(1) “Materials produced in a beneficiary country or countries” defined. For purposes of paragraph (a) of this section, the words materials produced in a beneficiary country or countries refer to those materials incorporated in an article which are either:
(3) Determination of cost or value of materials.
(i) The cost or value of materials produced in a beneficiary country or countries or in the customs territory of the United States includes:
(ii) Where a material is provided to the manufacturer without charge, or at less than fair market value, its cost or value shall be determined by computing the sum of:
(e) Direct costs of processing operations—(1) Items included. For purposes of paragraph (a) of this section, the words direct costs of processing operations mean those costs either directly incurred in, or which can be reasonably allocated to, the growth, production, manufacture, or assembly of the specific merchandise under consideration. Such costs include, but are not limited to the following, to the extent that they are includable in the appraised value of the imported merchandise:
(2) Items not included. For purposes of paragraph (a) of this section, the words “direct costs of processing operations” do not include items which are not directly attributable to the merchandise under consideration or are not costs of manufacturing the product. These include, but are not limited to: