Rule Summary: Requires dealers to use reasonable diligence to ascertain the best market for the subject security and buy or sell in that market so that the resultant price to the customer is as favorable as possible under prevailing market conditions.

Rule Summary: Establishes requirements relating to CUSIP numbers for dealers and, in competitive offerings, municipal advisors; requires underwriter participation in the New Issue Information Dissemination Service (NIIDS); and requires submission of certain information and documents related to auction rate securities and variable rate demand obligations to the SHORT system.