Rule Summary: Prescribes standard formulas for the computation of accrued interest, dollar price and yield; sets standards for accuracy; and establishes day-counting methods.

Rule Summary: Prohibits dealers from engaging in municipal securities business and municipal advisors from engaging in municipal advisory business with municipal entities if certain contributions have been made to officials of such municipal entities within the preceding two-year period, and requires dealers and municipal advisors to disclose certain political contributions and other information.