This is “Consumer Price Index for All Urban Consumers” or “CPI-U”.

“Core” Inflation Rate: This rate is based on CPI minus food & energy. Less volatile than the main inflation rate.

NYTimes coverage of inflation: http://www.nytimes.com/2008/01/16/business/16cnd-econ.html

Inflation Rate: This is the main inflation rate - year-over-year percentage change in “the” CPI.

Authoritative CPI: This index is the one that is generally referred to as “the” Consumer Price Index.