In other words, the mere fact that the financial markets understood that we could adjust the quantity of settlement cash in the banking system, thereby tightening or easing monetary conditions, was sufficient to produce a change in monetary conditions consistent with our objective of meeting the inflation target, without the need for any actual change in settlement cash.
It was in one sense the ultimate "no hands central banking", where we set no interest rate and no exchange rate, and left the target for settlement cash unchanged for many months on end.