Manager's often report "pro forma" or "non-GAAP" earnings as supplemental information when reporting their GAAP earnings. What information can a non-GAAP earnings number provide that a Gaap earnings number does not? Give examples of possible differnces that might exist between the two earnings numbers. Discuss potential advantages and disadvantages to using non-GAAP earnings to assess a firm's performance. Explain the SEC's position on non-GAAP earnings. Why might the SEC have instituted this sort of requirement?