Complex sentence: A "collective name" or "collective pseudonym" is one shared by two or more persons, for example the co-authors of a work, such as Ellery Queen, or Bourbaki.
Split into simpler sentences: A "collective name" or "collective pseudonym" is one shared by two or more persons. This is sometimes used by the co-authors of a work, such as Ellery Queen, or Bourbaki.