For example, in May 2003 the European Central Bank (ECB) clarified that in implementing its mandate of price stability, monetary policy would be aimed at maintaining inflation "below, but close to, 2 percent in the medium term" (European Central Bank, 2003). That clarification was welcomed by market participants and likely made it easier for the ECB to anchor inflation expectations.
As a final example, consider the evolution of the monetary policy framework in Canada.