The BoE has been striving to hit their 2% CPI target and has missed with the last 20 shots - not since August 2007 has inflation been under 2%. But in June they finally hit the target again: CPI 1.8% and RPI was -1.6%.
RPI is now the lowest ever recorded (records began in 1948.) However RPI isn't very interesting at the moment because it's mainly a function of the low base rate.
It remains to be seen whether the BoE just got lucky or will hit the target every month from now on.