The prospectus states the Fund seeks current income exempt from federal income tax and long-term capital appreciation. It invests at least 80% of net assets (plus borrowings for investment purposes) in securities generating federally tax-exempt income, a fundamental policy, and at least 60% of total assets in medium-grade or lower-rated or comparable unrated municipal securities. Investments in below-investment-grade securities are described as speculative. The Fund may use tender option bond financings and borrowings as leverage.