BlackRock High Yield Municipal Fund Institutional Shares (BlackRock HY Muni Fd I) 

This fund primarily focuses on municipal debt, dedicating a minimum of 80% of its total assets to these securities. It has the flexibility to invest in municipal bonds across the entire credit rating spectrum, including those without an official rating. Notably, at least 65% of its net assets are specifically channeled into municipal bonds that one or more independent rating agencies classify as medium to lower credit quality. Furthermore, the fund is authorized to allocate up to 10% of its holdings to distressed municipal securities.