How do I catalog a book on the vocalizations of frogs? I'm thinking that I should start with 597.89.

The comprehensive number for "Vocal communication--animals" is indexed under the vertebrate number, because vertebrates are the only kind of animals that communicate by vocal chords. It is built by following the footnote at 596 to its source. The asterisk at the heading "Chordata" leads to the footnote "*Add as instructed under 592-599." The frog number that you cited has the same footnote, and all asterisks in 592-599 lead to the same short table at the centered entry covering the span.

The first note in the centered entry says "add to each entry identified by * as follows:". (In Dewey, "add" means append, or "tack on to the end of.") The final number in the table is 1. Add 1 to the numbers in question, and you get 596.1 and 597.891, respectively. The note under 1 in the table says "Add to 1 the numbers following 591." That should send you looking for the animal communication numbers under 591. The main number for animal communication in general is 591.59, and 591.594 is the number for acoustical communication and animal sounds. Add --594 (the notation following 591) to the two numbers, and you have 596.1594 and 597.891594, respectively, for acoustical communication in vertebrates and frogs.

Footnotes are widely used in certain disciplines in Dewey. Following them to their destination is one of the main secrets of number building.

Last revised: 18 November 2003