A pen name, nom de plume, or literary double, is a pseudonym adopted by an author for various reasons. Authors may use a pen name to replace a long, difficult, or uninteresting name or a name likely to be confused with the name of another writer or notable individual, or to avoid overexposure. Authors who write in different styles use pen names to avoid confusing regular readers. Some female authors have used male pen names to ensure that their works were accepted by publishers or taken seriously. A pseudonym may also be used to protect the writer, primarily in the case of exposé books about espionage or crime.