Some prices in the CPI tend to vary widely from one period to the next, such as energy prices which can rise sharply in one period and then fall in the next. Price volatility can create noise in the picture of the underlying trend in price developments.
In order to strip out temporary inflation volatility, Norges Bank uses various indicators of underlying inflation. The main indicator of underlying inflation in Norges Bank's analyses is the CPI adjusted for tax changes and excluding energy products (CPI-ATE).
See the overview of developments in the CPI and different indicators of underlying inflation