repeating groupAny {attribute} that can have multiple values associated with a single instance of some {entity}. For example, a book might have multiple authors. In order to represent such a relationship in a {relational database}, it would be converted to "first normal form" as the first step in {database normalisation}. Each author of the book would then appear in a separate {row}, each of which also contained the book's {primary key}. (2001-04-10)