The Book Interchange Tag Suite (BITS) version 2.1 contains an XML model for STM books that is based on the Journal Article Tag Suite (JATS; ANSI/NISO Z39-96-2012) version 1.3. The intent of the BITS is to provide a common format in which publishers and archives can exchange book content, including book parts such as chapters. The Suite provides a set of XML schema modules that define elements and attributes for describing the textual and graphical content of books and book components as well as a package for book part interchange.

The spring-board for developing the BITS was the observation that a JATS-based XML book model would be useful to a wide variety of publishers of professional and scholarly books, especially but not exclusively to publishers who are already using one of the JATS journal article models and looking for a compatible model for their books.

The BITS Book Interchange DTD is a superset customization of the ANSI/NISO JATS Z39.96-2012 Journal Archiving and Interchange Tag Suite version 1.1d1, with added material to describe STM books, book components such as chapters, and information concerning the inclusion of books and book components in book series. The Tag Set describes both the metadata and the narrative content of a book, both the metadata and narrative content for book components, and collection-level metadata for book sets and book series, when a book part is associated with one or more such collections.

BITS is managed by the National Center for Biotechnology Information (NCBI) at the US National Library of Medicine (NLM). BITS is not a NISO standard.