General Introduction

The intent of the NLM Journal Archiving and Interchange Tag Suite is to provide a common format in which publishers and archives can exchange journal content. The Suite provides a set of XML schema modules that define elements and attributes for describing the textual and graphical content of journal articles as well as some non-article material such as letters, editorials, and book and product reviews.

Introduction to the Journal Archiving Tag Set


The Journal Archiving and Interchange Tag Set (“Journal Archiving Tag Set”) defines elements and attributes that describe the content and metadata of journal articles, including research and non-research articles, letters, editorials, and book and product reviews. The Tag Set allows for descriptions of the full article content or just the article header metadata.

The intent of the Archiving Tag Set is to “preserve the intellectual content of journals independent of the form in which that content was originally delivered”. This Tag Set enables an archive to capture structural and semantic components of existing material without modeling any particular sequence or textual format.

It was planned that Archiving could be used for conversion from a variety of journal source Tag Sets, with the intent of providing a single format:

  • in which publishers could deliver their content to a wide range of archives, and
  • into which archives could conveniently translate content from many publishers.

In order to enable description of the content used by the wide array of publishers, repositories, aggregators, etc., the Tag Set uses many loose structures, including some elements with nearly all content structures optional. Many attribute values in the Tag Set are data character values, accommodating any source values. Because some article components are prescriptive in nature, article metadata for example, the Archiving Tag Set includes a few completely generic structures for capturing semantic tagging that is not available natively in the Tag Set. Although publication order cannot always be preserved, particularly within the metadata, the Archiving Tag Set works harder than any of the other NLM Tag Sets in this Suite to allow almost any publication arrangement and to allow re-tagging as renaming without rearrangement during conversion.

The Archiving Tag Set has a distinct focus on conversion from multiple sources. That focus has made this Tag Set a large and inclusive one. Many elements have been created explicitly so that information tagged by publishers would not be discarded when they converted material from another Tag Set to this one (or one created from this Suite). Care has also been taken to provide several mechanisms (frequently, information classing attributes) to preserve the intellectual content of a document structure when that structure is converted from another Tag Set or schema to this one, even when there is no exact element equivalent of the structure.

The exact replication of the look and feel of any particular journal has not been a consideration. Therefore, many purely formatting mechanisms have not been included. At the same time, Archiving is intended to preserve observed content, without resorting to stylesheets or generation of textual elements. For that reason, labels, numbers, and symbols of tables, figures, sidebars, and the like can be recorded as elements, as can the punctuation and spaces inside bibliographic references and lists.


By design, this is a model for journal articles, such as the typical research article found in an STM journal, and not a model for complete journals. This Tag Set does not include an overarching model for a collection of articles. In addition, the following journal material is not described by this Tag Set:

  • Company, product, or service display advertising;
  • Job search or classified advertising;
  • Calendars, meeting schedules, and conference announcements (except as these can be tagged as ordinary articles, sub-articles, or sections within articles); and
  • Material specific to an individual journal, such as Author Guidelines, Policy and Scope statements, editorial or advisory boards, detailed indicia, etc.

Structural Overview

The Journal Archiving Tag Set defines a document that is a top-level component of a journal such as an article, a book or product review, or a letter to the editor. Each such document is composed of one or more parts; if there is more than one part, they must appear in the following order:

  • Front matter (required). The article front matter contains the metadata for the article (also called article header information), for example, the article title, the journal in which it appears, the date and issue of publication for that issue of that journal, a copyright statement, etc. This is not textual front matter as appears in books, rather this is bibliographic information about the article and the journal in which it was published.
  • Body of the article (optional). The body of the article is the main textual and graphic content of the article. This usually consists of paragraphs and sections, which may themselves contain figures, tables, sidebars (boxed text), etc. The body of the article is optional to accommodate those repositories that just keep article header information and do not tag the textual content.
  • Back matter for the article (optional). If present, the article back matter contains information that is ancillary to the main text, such as a glossary, appendix, or list of cited references.
  • Floating Material (optional). A publisher may choose to place all the floating objects in an article and its back matter (such as tables, figures, boxed text sidebars, etc.) into a separate container element outside the narrative flow for convenience of processing.
  • Following the front, body, back, and floating material, there may be either one or more responses to the article or one or more subordinate articles:
    • Response. A response is a commentary on the article itself, for example, an opinion from an editor on the importance of the article or a reply from the original author to a letter concerning his article.
    • Sub-article. A sub-article is a small article that is completely contained inside another article.

Tag Sets Developed from the Suite

This Tag Set is one of several created from the Suite. Information about these Tag Sets may be found at the following site:


Because access for a wide range of output devices, as well as for the visually impaired, is becoming more and more important in the STM journal community, the modules in the Archiving and Interchange Suite were designed to follow, as much as possible, the W3C Web Content Accessibility Guidelines 2.0 working draft (22 August 2002), which was the latest accessibility specification available when the Suite was initially constructed. This Specification specifies accessibility guidelines on many levels from design through application. The guidelines which pertain to the modeling of materials were followed to at least Level-2 compliance. For example, a Long Description <long-desc> element was defined as part of many other elements, such as Figure <fig>, so it can be added not only to all figures and other graphical objects, but to any section of the text (for example, to a Boxed Text <boxed-text>) to provide an accessible description of the object. The @xml:lang attribute was added to all section-level elements and many paragraph-level elements to permit explicit indication of the language of the content, as required by these guidelines. The Abbreviation or Acronym <abbrev> element (also to be used for acronyms) was added to meet Checkpoint 4.3.

How to Read This Tag Library

Terms and Definitions


Elements are nouns, like “speech” and “speaker”, that represent components of journal articles, the articles themselves, and accompanying metadata.


Attributes hold facts about an element, such as which type of list (e.g., numbered, bulleted, or plain) is being requested when using the List <list> tag, or the name of a pointer to an external file that contains an image. Each attribute has both a name (e.g., @list-type) and a value (e.g., “bullet”).


Data about the data, for example, bibliographic information. The distinction is between metadata elements which describe an article (such as the name of the journal in which an article was published) versus elements which contain the textual and graphical content of the article.

How To Start Using This Tag Library

The Journal Archiving Tag Set is available on the NLM Journal Archiving and Interchange Tag Suite Website including: the Tag Set models expressed as DTDs, XSD schemas, and RELAX NG schemas; and this Tag Library documentation (a set of linked HTML files). The DTD file delivery includes the Journal Archiving DTD; the customization files needed for the Journal Archiving Tag Set to override the declarations in the modular Suite, any new modules that define Tag-Set-specific elements, and the modules that comprise the full Suite.

How you use the documentation will depend on what you need to learn about the modules and the Tag Set.

Learn the Tag Set

If you want to learn about the elements and the attributes in this Tag Set so you can tag documents or learn how the journal article model is constructed, here is a good way to start.

  • Read the Tag Library General Introduction, taking particular note of the next section that describes the parts of the Tag Library so you will know what resources are available.
  • Next, if you do not know the symbols used in the Document Hierarchy diagrams, read the “Key to the Near & Far® Diagrams”.
  • Scan the Document Hierarchy diagrams to get a good sense of the top-level elements and their contents. (Find what is inside an <article>, now what is inside each of the four large pieces of an article, keep working your way down.)
  • Pick an element from one of the diagrams. Look up the element in the Elements Section to find the full name of the element, its definition, usage notes, content allowed, and any attributes. Look up one of the attributes to find its full name, usage notes, and potential values.

Finally, if you are interested in conversion from a particular source:

  • Look at an article in a printed or online journal or look at the DTD/schema for the other journal.
    • Can all the information you want to store from an article fit into the models shown in the diagrams?
    • Do you have, or know how to get, all the information the models require? Will that information always be available for documents that are complete and correct?
    • How difficult will it be to identify the parts of the information using the elements and attributes described in these models? Would changes to one or more models make this easier?
  • Now look at some non-article content, such as a news column, a book review, or some letters to the editor. Are there tags to handle all these article types and all their components?

Structure of This Tag Library

This Tag Library contains the following sections:

How To Use (Read Me First

How to make best use of this Tag Library to reference XML tags, become familiar with the Archiving Tag Set as a whole, or see examples of recommended usage.


This introduction to the contents of this Tag Library, to the design philosophy and intended usage of the Archiving and Interchange Suite, and to the Journal Archiving Tag Set.

Elements Section

Descriptions of the elements used in the Journal Archiving Tag Set and the parts of the Archiving and Interchange Suite used in this Tag Set. The element descriptions are listed in alphabetical order by tag name.

[Note: Each element has two names: a “tag name” (formally called an element-type name) that is used in tagged documents, in the DTDs/schemas, and by XML software; and an “element name” (usually longer) that provides a fuller, more descriptive name for the benefit of human readers. For example, a tag name might be <disp-quote> with the corresponding element name Quote, Displayed, or a tag name might be <verse-group> with the corresponding element name Verse Form for Poetry.]

Attributes Section

Descriptions of the attributes in the Journal Archiving Tag Set. Like elements, attributes also have two names: the shorter machine-readable one and a (usually longer) human-readable one. Attributes are listed in order by the shorter, machine-readable names. For example, the attribute short name @list-type instead of the more informal, easier to read: Type of List.

Parameter Entity Section

Names (with occasional descriptions) and contents of the parameter entities in the Tag Set modules.

Document Hierarchy Diagrams

Tree-like graphical representations of the content of many elements. This can be a fast, visual way to determine the structure of an article or of any element within an article.

Common Tagging Practice

Tips, tricks, hints, and examples of how (and why) to tag certain structures using this Tag Set.

Implementing This Tag Set

Implementor’s instructions for using the Tag Set, customizing this Tag Set, or making derivative tag sets based on this one.

Change Report: Version 3.0

Detailed information about the changes between version 3.0 and 2.3 for both for the base Suite and the Journal Archiving Tag Set. The report has two sections: the first identifies how each element changed between the two versions; the second provides an implementor’s view of the changes in parameter entities, content models, attribute lists and/or values, etc.


The Journal Archiving Tag Set is available in three forms: an XML Document Type Definition (DTD); a W3C XML Schema (XSD); and a RELAX NG Schema (RNG). Each of these formats is available in two forms: a zipped file containing a downloadable version of the schema (often in multiple files), and a readable/browsable version in which the internal markup has been escaped.

Context Table

A listing of where each element may be used. All elements in the Tag Set are given in a single alphabetical list.

The Context Table is formatted in two columns. The first column (“This Element”) names an element, with the name shown in pointy brackets. In the second column (“May Be Contained In”) for each element is an alphabetical list of all the elements in which the first column element may occur. For example, if the first column contains the element <front> and the second column contains only the <article> element, this means that the <front> element may only be used directly inside an <article>. Most elements may be used inside more than one other element. For example, the element <def> (a definition) may be used inside the <abbrev> and the <def-item> elements.

The Context Table contains the same information that is found on each element page under the heading “May Be Contained In”.


Where to find elements, tags, and terms used in this Tag Library. Includes synonyms (terms not used in this Tag Set) that direct the reader to elements used in this Tag Library, for example, “author” is paired with Contributor <contrib>.

Tag Library Typographic Conventions

<alt-text> The tag name of an element (written in lower case with the entire name surrounded by “< >”)
Alternate Text Name (For a Figure, Etc.) The element name (long descriptive name of an element) or the descriptive name of an attribute (written in title case, with important words capitalized, and the words separated by spaces)
must not Emphasis to stress a point

Changes in Version 3.0

This version of the Tag Suite and the derivative Tag Sets marks a significant departure from all previous versions. Before now, all changes to the Suite had been fully backward compatible. That meant that while the Suite changed and grew, no document tagged according to a particular Tag Set was invalid because of any new or changed models. For the first time, this is not the case. Version 3.0 is non-backward compatible, meaning documents which were valid against any previous version may not be valid against this version. Some users will choose to keep their existing documents as they are, valid according to an older version of the Tag Set and to use the new Tag Set for future documents. Some users will convert their existing documents to the new Tag Set, a conversion that we believe will be mostly automatable in most cases. It is possible that some users will choose to continue to use an older version of the Tag Set.

The rationales behind the changes vary, but all were made with the intent to make it easier to move forward. There has been nearly six years of experience working with this Tag Set on journal articles as varied as medicine, biotechnology, and physics. Many of the changes were of the “if we had known then what we know now” variety. Others were changes that have been obvious improvements for four or five years, but could not be made within the scope of normal maintenance because they would have been non-backward compatible.

Version 3.0 includes the regular scope changes and additions that have been the subject of previous version releases. For example, a new funding model (<funding-group>) has been added to reflect the changing needs of the community. In addition to this kind of change, version 3.0 changes also include:

A report listing all changes is available in the Change Report section.


We thank, Molecular Biology of the Cell, and The Proceedings of the National Academy of Sciences of the U.S.A. for providing the sample articles used in this Tag Library.