 Since 1971 the runners-up are called Caldecott Honor Books, but some runners-up had been identified annually and all those runners-up were retroactively named Caldecott Honor Books.The number of Honors or runners-up had always been one to five, and it had been two to four since 1994, until five were named in 2013 and six in 2015.The Honor Books must be a subset of the runners-up on the final ballot, either the leading runners-up on that ballot or the leaders on one further ballot that excludes the winner.