William Safran in an article published in 1991, set out six rules to distinguish diasporas from migrant communities. These included criteria that the group maintains a myth or collective memory of their homeland; they regard their ancestral homeland as their true home, to which they will eventually return; being committed to the restoration or maintenance of that homeland, and they relate "personally or vicariously" to the homeland to a point where it shapes their identity. While Safran's definitions were influenced by the idea of the Jewish diaspora, he recognised the expanding use of the term.