v3.26.1
Shareholder Report, Holdings (Details)
May 31, 2026
C000001667 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.10% [1]
C000001667 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.00% [1]
C000001667 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 17.00% [1]
C000001667 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.50% [1]
C000001667 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 48.20% [1]
C000001667 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.20% [1]
C000001667 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000137705 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.10% [2]
C000137705 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.00% [2]
C000137705 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 17.00% [2]
C000137705 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.50% [2]
C000137705 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 48.20% [2]
C000137705 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.20% [2]
C000137705 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001664 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.10% [3]
C000001664 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.00% [3]
C000001664 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 17.00% [3]
C000001664 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.50% [3]
C000001664 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 48.20% [3]
C000001664 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.20% [3]
C000001664 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001668 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.50% [4],[5]
C000001668 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [4],[5]
C000001668 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.50% [4],[5]
C000001668 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 57.00% [4],[5]
C000001668 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50% [4],[5]
C000001668 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000137706 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.50% [6],[7]
C000137706 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [6],[7]
C000137706 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.50% [6],[7]
C000137706 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 57.00% [6],[7]
C000137706 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50% [6],[7]
C000137706 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001671 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.50% [8],[9]
C000001671 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [8],[9]
C000001671 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 23.50% [8],[9]
C000001671 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 57.00% [8],[9]
C000001671 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50% [8],[9]
C000001671 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001675 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [10]
C000001675 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20% [10]
C000001675 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.60% [10]
C000001675 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.10% [10]
C000001675 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 75.10% [10]
C000001675 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.50% [10]
C000001675 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000137707 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [11]
C000137707 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20% [11]
C000137707 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.60% [11]
C000137707 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.10% [11]
C000137707 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 75.10% [11]
C000137707 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.50% [11]
C000137707 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001672 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [12]
C000001672 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20% [12]
C000001672 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.60% [12]
C000001672 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.10% [12]
C000001672 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 75.10% [12]
C000001672 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.50% [12]
C000001672 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001676 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.10% [13]
C000001676 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40% [13]
C000001676 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [13]
C000001676 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.60% [13]
C000001676 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 53.50% [13]
C000001676 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.90% [13]
C000001676 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000137708 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.10% [14]
C000137708 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40% [14]
C000137708 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [14]
C000137708 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.60% [14]
C000137708 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 53.50% [14]
C000137708 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.90% [14]
C000137708 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001679 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.10% [15]
C000001679 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40% [15]
C000001679 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.50% [15]
C000001679 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 21.60% [15]
C000001679 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 53.50% [15]
C000001679 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.90% [15]
C000001679 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001683 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.90% [16]
C000001683 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.20% [16]
C000001683 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.90% [16]
C000001683 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.40% [16]
C000001683 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 54.20% [16]
C000001683 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 15.40% [16]
C000001683 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000137709 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.90% [17]
C000137709 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.20% [17]
C000137709 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.90% [17]
C000137709 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.40% [17]
C000137709 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 54.20% [17]
C000137709 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 15.40% [17]
C000137709 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001680 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.90% [18]
C000001680 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.20% [18]
C000001680 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.90% [18]
C000001680 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.40% [18]
C000001680 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 54.20% [18]
C000001680 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 15.40% [18]
C000001680 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 100.00%
C000001684 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.00% [19],[20]
C000001684 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 18.70% [19],[20]
C000001684 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 22.00% [19],[20]
C000001684 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.50% [19],[20]
C000001684 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00% [19],[20]
C000001684 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [19],[20]
C000001684 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 98.20%
C000001684 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [21]
C000137710 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.00% [22],[23]
C000137710 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 18.70% [22],[23]
C000137710 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 22.00% [22],[23]
C000137710 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.50% [22],[23]
C000137710 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00% [22],[23]
C000137710 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [22],[23]
C000137710 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 98.20%
C000137710 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [24]
C000001687 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.00% [25],[26]
C000001687 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 18.70% [25],[26]
C000001687 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 22.00% [25],[26]
C000001687 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 36.50% [25],[26]
C000001687 [Member] | Standard & Poor's, AAA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00% [25],[26]
C000001687 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [25],[26]
C000001687 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 98.20%
C000001687 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80% [27]
[1] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[2] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[3] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[4] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[5] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[6] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[7] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[8] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[9] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[10] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[11] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[12] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[13] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[14] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[15] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[16] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[17] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[18] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[19] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[20] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[21] Affiliated investment.
[22] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[23] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[24] Affiliated investment.
[25] The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
[26] Total investments include the Fund’s assets attributable to financial leverage. For these purposes, financial leverage includes the Fund’s investments in the residual interest certificates (also called inverse floating rate securities) in tender option bond (TOB) trusts, including the portion of assets held by a TOB trust that has been effectively financed by the trust’s issuance of floating rate securities.
[27] Affiliated investment.