The Latest version of DAISY merged with EPUB3. Since EPUB3 is not always accessible, an accessible EPUB3 book may be called a DAISY book.
EPUB3 is accepted by iBooks, Kobo, Google Play, SONY EBOOKS, etc. Amazon accepts EPUB3 format from publishers but adds proprietary format wrapper to keep users in Kindle players.
In principle, all eBook vendors accepts EPUB3 now.
Promotion of accessible EPUB3 contents is important.