Objective: This paper analyses and assesses current trends in using and exploiting metadata in the search and organization mechanisms of digital books, on distribution platforms and in ebook devices or applications. On the basis of their findings, the writers make a series of recommendations for adopting a practical and flexible approach to assigning metadata in the framework of the EPUB3 metadata standard.
-- Methodology: The writers manually revised the data incorporated on the platforms Amazon, iTunes Store and Project Gutenberg and in the ebook applications Adobe Digital Editions, Apple's iBooks, AZARDI, Calibre and Readium, examining exploration systems and book retrieval systems by keyword, item and collection (personal or external libraries).
-- Results: The distribution platforms make no provision for the metadata defined by the EPUB3 standard and included in the same document in order to develop the description of the product. By contrast, ebook applications do take account of these data, even though they make minimal use of them in book search and organization functions. The writers therefore recommend authors and editors to incorporate the metadata that are obligatory according to the EPUB 3 standard, in order to allow files to be validated, but avoid using semantic enrichment mechanisms and assign single values to each element.