High Quality Content by WIKIPEDIA articles! DTBook (an acronym for DAISY Digital Talking Book) or DAISY XML is a XML-based document file format. It is used in EPUB e-books and DAISY Digital Talking Book, as well as other places. Unlike other document file formats such as ODF DTBook puts a strong emphasis on structural encoding, but in comparison to other structural file formats such as DocBook and TEI it is fairly simple.