What is "wagner-werk-verzeichnis"

The Wagner-Werk-Verzeichnis ("Catalogue of Wagner's Works"), usually shortened to WWV, is an index and musicological guide to the 113 musical compositions and works for the stage of Richard Wagner compiled by John Deathridge, Martin Geck, and Egon Voss.

The catalogue is based on evidence compiled from original manuscripts of Wagner's writings and the examination of all drafts, sketches, and compositions. It also includes guidance on various editions of published works and explanations of historical performance practices.

For the full list, see List of compositions by Richard Wagner.