The non-profits PEN America and the American Library Association keep a catalog of banned books in the United States up to the 2021–22 academic year. In this 1 academic year alone, 1600+ books were irregularly banned from school districts across America.
Irregular bans tend to be ideologically driven. They are supplemental to and fall outside of the standard book exclusion process (e.g. standard exclusions prevent books that promote violent, hateful, or “mature/17+” topics from being placed on school bookshelves). Below, we’ve provided a sample of irregularly banned books in 2021–22: