The following debt fund categories use credit ratings as per SEBI: Corporate Bond Fund: Minimum 80% investment in corporate bonds only in AA+ and above rated corporate bonds Credit Risk Fund: Minimum 65% investment in corporate bonds, only in AA and below rated corporate bonds Gilt Fund: Minimum 80% in G-secs, across maturities Gilt Fund with 10-year constant Duration: Minimum 80% in G-secs, such that the Macaulay duration of the portfolio is equal to 10 years