Where General Note 26, subdivision (n), HTSUS, sets forth a rule that specifies a regional value content test for a good, the regional value content of such good may be calculated, at the choice of the person claiming the tariff treatment authorized by this note for such good, on the basis of the build-down method or the build-up method described in this section, unless otherwise specified in the note.

(a) Build-down method. For the build-down method, the regional value content must be calculated on the basis of the formula RVC = ((AV-VNM)/AV) × 100, where RVC is the regional value content, expressed as a percentage; AV is the adjusted value; and VNM is the value of non-originating materials used by the producer in the production of the good; or

(b) Build-up method. For the build-up method, the regional value content must be calculated on the basis of the formula RVC = (VOM/AV) × 100, where RVC is the regional value content, expressed as a percentage; AV is the adjusted value; and VOM is the value of originating materials used by the producer in the production of the good.