A legal opinion is a statement as to legality, written by an authorized official such as a city attorney or an attorney general. In the context of municipal bond issuances, it typically pertains to the legality of the bond issue, often prepared by a law firm specializing in public borrowings.
A rating agency is an organization that monitors the credit backing of bond issues and other forms of public borrowings. It also provides ratings on the risks involved in holding specific stocks. Well-known rating agencies include Standard & Poor's, Moody's, and Fitch.
