High schools in America undergo accreditation every few years to ensure that they're meeting all the standards and abiding by all the rules set forth by accrediting authorities to ensure that they meet a certain standard. For example, the high school I went to in Lake Forest, California was/is accredited by the Western Association of Schools and Colleges (WASC) -- which is the "accrediting authority" for my high school. Every high school has one, and usually all the high schools in a particular state or region have the same accrediting authority. The people working in the office at your high school can probably give you more information as to which accrediting authority your high school is accredited by.