* Is it a ban on availability? Meaning the school won't make the book available to students (e.g. in a school library).
* Is it a ban on integration into curriculum? Meaning the school has decided that no teacher may require students to read the book as a course requirement.
* Is it a ban on REQUIRED integration into curriculum? Meaning the school has decided that it isn't going to force teachers to require students to read the book, but each individual teacher may still choose to do so at their discretion.
* Is it a ban on possession? Meaning if you bring the book into school, it will be confiscated.
And then, of course, there are further distinctions.
A particular book might be appropriate for some mature AP English students who are preparing to enter college in the fall, but inappropriate for most middle schoolers. So let's say you have a school that's grades 7-12, with a shared library. Does the librarian determine appropriateness based on whether it's inappropriate for none/some/most/all?
I'm an author of several books, and I tend to be against outright bans. That said, I'm the parent of a 12-year-old who reads at a mid-high-school level, but has the emotional maturity of a kindergartener, and I can absolutely understand where parents are coming from when they hear about books being integrated into curricula that they know their kids don't have the maturity to handle.