Strategy. Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in a diversified portfolio of municipal obligations, the interest on which is exempt from regular federal income tax (the 80% Policy). In seeking the Funds investment objective, the portfolio managers emphasize tax-exempt income. The Fund normally invests in municipal obligations rated in the three highest rating categories (those rated A or higher by S&P Global Ratings (S&P), Fitch Ratings (Fitch) or Moodys Investors Service, Inc. (Moodys)) or, if unrated, determined by the investment adviser or sub-adviser to be of comparable quality at the time of purchase. The Fund may invest up to 15% of its net assets in municipal obligations … Show more… Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in a diversified portfolio of municipal obligations, the interest on which is exempt from regular federal income tax (the 80% Policy). In seeking the Funds investment objective, the portfolio managers emphasize tax-exempt income. The Fund normally invests in municipal obligations rated in the three highest rating categories (those rated A or higher by S&P Global Ratings (S&P), Fitch Ratings (Fitch) or Moodys Investors Service, Inc. (Moodys)) or, if unrated, determined by the investment adviser or sub-adviser to be of comparable quality at the time of purchase. The Fund may invest up to 15% of its net assets in municipal obligations rated BBB by S&P, Fitch or Moodys or, if unrated, determined by the investment adviser or sub-adviser to be of comparable quality. The Fund will not invest more than 50% of its net assets in municipal obligations rated A at the time of purchase by S&P, Fitch or Moodys or, if unrated, determined by the investment adviser or sub-adviser to be of comparable quality. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. The Fund may continue to hold securities that are downgraded (including bonds downgraded to below investment grade credit quality (junk bonds)) if the sub-adviser believes it would be advantageous to do so. The Fund will not invest in a municipal obligation the interest on which the Funds sub-adviser believes is subject to the federal alternative minimum tax. With respect to its investment in municipal obligations, the Fund invests primarily in general obligation or revenue bonds. The Fund currently targets an average portfolio duration of approximately 2 - 4.5 years and an average weighted portfolio maturity of approximately 3 - 6 years, but may invest in securities of any maturity or duration, and may in the future alter its maturity or duration target range. The Fund may use various techniques to shorten or lengthen its dollar-weighted average portfolio duration, including the acquisition of municipal obligations at a premium or discount. The portfolio managers generally will seek to enhance after-tax total return by actively engaging in relative value trading within the portfolio to take advantage of price opportunities in the markets for municipal obligations and use relative value analysis to assist them in making decisions to purchase or sell investments. With respect to 20% of its net assets, the Fund may invest in municipal obligations that are not exempt from regular federal income tax, direct obligations of the U.S. Treasury and/or obligations of U.S. Government agencies, instrumentalities and government-sponsored enterprises. The Fund may hold cash and may invest in cash equivalents and money market instruments. The sub-advisers process for selecting municipal obligations for purchase and sale generally includes consideration of the creditworthiness of the issuer or person obligated to repay the obligation. In evaluating creditworthiness, the sub-adviser considers ratings assigned by rating agencies and generally performs additional credit and investment analysis. The portfolio managers may also trade securities to minimize taxable capital gains to shareholders. The portfolio managers may sell a security when its credit quality declines, when the remaining maturity of a fixed-income security reaches a certain point or to pursue more attractive investment options. Show less