With the removal of the word «legal», this could be the definition of the
citation system for any
academic discipline: the MLA style for the humanities (MLA Handbook for Writers of Research Papers, 7th ed, Modern Language Association, 2009), the APA style for the social sciences (Publication
Manual of the American Psychological Association, 6th ed, 2010), or the CSE style for science writers (Scientific Style and Format: The CSE
Manual for Writers, Editors and Publishers, 7th ed, Council of Science Editors, 2006).