On Jan. 27, nonprofit organization PEN America released a list of 23 picture book titles that most frequently banned during the school year — see all of the titles here

Banned in libraries: This is a process where administrators or school boards remove individual titles from school libraries where they were previously available. Books in this category are not necessarily banned from classroom curriculum and the books can still be available at different grade levels.

Free-speech groups argue the ban violates constitutional rights.

The employee who filed the suit told FOX31's Gabby Easterwood that she felt the ban was racist and discriminatory. She was fired through a reduction of workforce, according to the district.