Index librorum prohibitorum was a list of books that were banned or censored by the Catholic Church. Some synonyms for "index librorum prohibitorum" include a blacklist of books, a catalog of prohibited literature, a list of forbidden texts, or a register of censored works. These synonyms all refer to a collection of texts that were deemed inappropriate or dangerous by authorities. Other terms that could be associated with the index librorum prohibitorum might include censorship, book burning, or intellectual repression. Though such lists are no longer common, the idea of banning books or limiting free expression remains controversial and relevant today.