The clear mandate of the bank in the conduct of monetary policy is to achieve the 2% CPI inflation target. That is the clear mandate, that's how we're judged, and that's how we're held accountable. Related to that, but not always overlapping it, we have an intervention policy agreed to by the Government of Canada. It provides for intervention in the foreign exchange markets under two scenarios: gapping in the foreign exchange market, which is a relatively rare occurrence, given the liquidity of those markets; and market volatility sufficient to create the prospect of serious impact on economic growth. These are conditions not to be taken lightly.
On October 27th, 2009. See this statement in context.