Yesterday’s report by Standard & Poor’s on the U.S. government’s credit rating is driving headlines. You can learn a lot more from reading the primary source document than from news coverage of it.

Here is what S&P did:

On April 18, 2011, Standard & Poor’s Ratings Services affirmed its ‘AAA’ long-term and ‘A-1+’ short-term sovereign credit ratings on the United States of America and revised its outlook on the long-term rating to negative from stable.

The news is in the latter part: S&P downgraded its “outlook on the long-term