When asked to comment on the exchange rate to use for interest, dividends and capital gains, CRA stated, after referring to the reference in the definition to "another rate of exchange that is acceptable" (TaxInterpretations translation):
[A]n average rate of exchange could qualify in this regard. However, we do not accept using an average exchange rate respecting the calculation of capital gains and losses. Thus…all amounts expressed in a foreign currency before being taken into account in the calculation of such gains or losses (namely, the adjusted cost base, the proceeds of disposition and the expenses of the disposition) must be converted into Canadian dollars in accordance with the "relevant spot rate" for the day or days when they arose. This result accords with the principles elaborated…in Gaynor.