Typically, this fund commits a minimum of 80% of its total assets (inclusive of any capital acquired through borrowing for investment) to municipal bonds that generate interest exempt from regular federal income tax. The portfolio also maintains the flexibility to allocate up to 20% of its assets to other debt instruments. These may include, but are not limited to, taxable municipal obligations, U.S. Treasury securities, and various debt issued by the U.S. government, its agencies, and instrumentalities.