Public pension data have become more complex as GASB, the rating agencies, and governments themselves may all be using different sets of pension numbers for different purposes. The GFOA and other leading national associations representing state and local governments, agencies, and officials have developed a one-page summary to help everyone concerned understand the differences among these numbers, the intended purpose and audience, and new resources available to lawmakers to address pension funding.
http://gfoa.org/downloads/JointFundingGuidelinesOverview.pdf