From the New York Times:
After the meeting, however, Mrs. Hahn said she felt her arguments had been given short shrift, and she met privately with Mr. Nelson, the board president, to push the idea of a rating system for schoolbooks, similar to what the Motion Picture Association of America does for films. And on May 18, the board rejected the English department's new policy for book challenges and asked that Mrs. Hahn's requests be accommodated: that reading lists made available to parents include a ratings system, plot summaries of all assigned books, and the identification of any potentially objectionable content.
"Potentially objectionable content". Yeah, that's not opening a whole new can of worms or anything.