what librarians put in the author's field when writing index cards for a work with many different authors. A good example is the Bible or an anthology.
The various authors device is employed when a work has many disparate authors, all of them on the same level: for example, a novel with an author and a co-author would not use it - here one would simply list the two authors in order of importance.
Neither would an edition of Eliot's poetry accompanied by a selection of criticism.
Notice that any reasonable classification system will have a way of saying that a book was written by
various editors, but edited or compiled by a certain person.
In italian libraries it is abbreviated as AA.VV..