851.22.4R10. For the purposes of Division III, if the terms of a specified debt obligation of a taxpayer give the taxpayer the right to exchange the obligation for shares of the debtor or of a corporation related to the debtor,(a) subject to paragraph b, the right is disregarded, whether it has been exercised or not; and
(b) if 5% or more of the cost of the obligation to the taxpayer is attributable to the right, the cost of the obligation to the taxpayer is deemed to equal the amount by which the cost otherwise determined exceeds the portion of the cost attributable to the right.