SIFMA provides comments to the Securities and Exchange Commission (SEC) on the proposed rule changes filed by the Municipal Securities Rulemaking Board (MSRB) consisting of a restatement of an Interpretive Notice concerning the application of MSRB Rule G-17 (Conduct of Municipal Securities and Municipal Advisory Activities) to Sophisticated Municipal Market Professionals (SMMPs), SR-MSRB-2012-05.  SIFMA commends the MSRB for proposing a revised and expanded definition of SMMP and urges the SEC to swiftly move forward with its adoption.