NLMBITS is an XML tag suite for encoding the full text, metadata, and structural elements of books and book components. Maintained by the National Library of Medicine, it extends the Journal Article Tag Suite (JATS) to address the unique structural requirements of monographs, edited volumes, and book series in scientific, technical, and medical publishing.
Background
The Book Interchange Tag Suite was developed by NLM/NCBI as a companion to JATS, recognizing that while journal articles and books share much of their textual vocabulary, books require additional structures for chapters, parts, front matter, back matter, and collection-level metadata. BITS was first released around 2012 and has tracked JATS versions, with each BITS release being based on the corresponding JATS version. The current version, BITS 2.2, is based on JATS 1.4 (ANSI/NISO Z39.96-2024).
Purpose & Scope
BITS provides a common format for publishers and archives to exchange book content. Its scope includes:
- Complete books with front matter, body, and back matter
- Individual book parts (chapters, sections) as standalone interchange units
- Collection-level metadata for book series
- Mixed content models supporting text, tables, figures, equations, and cross-references
- Packaging structures for bundling book parts with their metadata
The tag suite is designed primarily for the STM (scientific, technical, medical) publishing domain but is general enough for other book content.
Serializations & Technical Formats
BITS schemas are available in three equivalent schema languages:
| Schema Language | Description |
|---|---|
| DTD | Document Type Definition |
| RELAX NG (RNG) | Regular Language for XML Next Generation |
| W3C XML Schema (XSD) | XML Schema Definition |
All schema files are available via the NLM FTP server and at stable URIs for each version. There is no preference among the three; implementers choose based on their toolchain.
Governance & Maintenance
BITS is maintained by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM), part of the National Institutes of Health. Updates track the JATS release cycle. Feedback is welcomed through the JATS Discussion List, a public mailing list hosted by Mulberry Technologies.
Notable Implementations
BITS is used by publishers and archives exchanging STM book content, particularly those already working with JATS for journal articles. The NLM Bookshelf, which provides free online access to books and documents in life science and healthcare, uses BITS-compatible XML. Publishers in the biomedical and life sciences domain use BITS for content interchange and long-term archiving.
Related Standards
- JATS — BITS is a direct extension of JATS, sharing its element vocabulary and architectural conventions
- NISO STS — Another JATS extension, focused on standards documents rather than books