If your goal is what to have parents decide what their kids can read then the only way to do that is to have the shared (e.g. school) library carry the commonly agreed upon subset and individual parents who want their kids to have access to more to provide those more controversial book at home. The only reason to call to have books other parents don't want their kids to be exposed to in the school library is if you want to override their choice and make those books available to kids other than yours as well.