21 November 2011 External T.I. 2011-0422191E5 F - Price adjustment clause and redemption of shares -- summary under Effective Date

if preferred shares with a redemption amount which is subject to a price adjustment clause are redeemed before there is an upward adjustment to the redemption amount pursuant to that clause, a payment of the resulting additional amount will be included in the shareholder's income in the year of receipt under s 84(3).