You can automatically create a glossary for your book on any Pressbooks network, add DOIs to your book’s metadata, and customize the automatic section labels for your book’s parts and chapters. Find this and more in the Pressbooks 5.6.0 update:
https://pressbooks.education/news/2018/11/whats-new-on-pressbooksedu-glossary-creation-doi-integration-and-more/