Labels are a subjective judgment, and it is not the responsibility of the librarian to serve as a rating system. A related concept is restricted access. According to the principle of intellectual freedom, neither the library nor the librarian should be responsible for determining who may have access to materials held by the library. Defining pornography and debating the value of restricted access, especially for children, are common issues in libraries. This is another complicated debate, since people may have different definitions of what is racist.
Some racist materials have great historical value for research.
Changes in societal values can affect the perceived value of materials that were written in different times. The collection should provide materials representing both sides of controversial issues. Recently the children's book Daddy's Roommat e came under fire for portraying homosexuality as an acceptable lifestyle. Groups who wanted the book censored found an alternative title, Alphie's House , which called homosexuality a curable disease. The concept of intellectual freedom says that both books have the right to be in a library, regardless of personal opinions on the issue of homosexuality.