Supplementary Material

Container element for a description of, and possibly a pointer to, external resources that support the article, but which are not part of the content of the article.


Defining Supplementary Material: Supplemental material is used to add detail, background, or context to an article by providing, for example, multimedia objects such as audio clips and applets; additional XML-tagged sections, tables, or figures; raw data in a spreadsheet, or a software application in a repository. Supplementary material includes resources such as the following:

An object that cannot be fully represented in print (such as a movie, sound file, or animation) should not automatically be considered supplemental. If the object is necessary for understanding the article (in other words, the object is “integral” as defined by NISO RP-15-2013 discussed below) it should be tagged at the appropriate location in the text using the <media> element.

Contents of the Supplementary Material Element: The <supplementary-material> element does not contain the supplementary object(s); even if the objects are expressed in XML; supplementary objects are external to the XML article rather than part of the XML article. The <supplementary-material> element contains descriptions of the object(s), and it may also, but is not required to, contain a pointer to the objects(s). For example, if the supplementary object is an additional graphic, that graphic is described in the supplementary material but not held there. The <graphic> element that is permissible inside <supplementary-material> is intended for a description of an object, not to hold the object. For example, a <supplementary-material> element could contain a description of an animation, including the first frame of the animation (tagged as a <graphic> element), a caption describing the animation, and a cross-reference made to the external file that held the full animation.

Usage: The element is used in two contexts:

Typing: The @mimetype attribute may be used to identify a file type for a <supplementary-material> element.

Relationship to NISO Supplemental Material Best Practices NISO RP-15-2013 Recommended Practices for Online Supplemental Journal Article Materials (https://groups.niso.org/higherlogic/ws/public/download/10055) and NISO JATS have identical concepts for “additional” and “integral” material that comprises an article, but slightly different practice concerning whether supplementary material is integral or additional.

Both NISO JATS and NISO RP-15-2013 define

The two differ in that, for NISO RP-15-2013, “integral content” may be part of an article or it may be part of the supplementary material for the article, that is, NISO RP-15-2013 allows supplementary material to be “integral”. For NISO JATS, which predates NISO RP-15-2013, all integral material is part of the base article (inside the <article> element) and all supplementary material is external to the article.

Relation to Other Journal Tag Sets: The <supplementary-material> element has a similar function to the <audiovisual> element in some XML tag sets and the <unprinted-item> element (used only for electronic files) in other tag sets.


content-type Type of Content
id Document Internal Identifier
mime-subtype Mime Subtype
mimetype Mime Type
orientation Orientation
position Position
specific-use Specific Use
xlink:actuate Actuating the Link
xlink:href Href (Linking Mechanism)
xlink:role Role of the Link
xlink:show Showing the Link
xlink:title Title of the Link
xlink:type Type of Link
xmlns:xlink XLink Namespace Declaration
xml:base Base
xml:lang Language

Related Elements

This Suite contains several elements that can describe and point to graphic material: <graphic>, <inline-graphic>, <media>, <supplementary-material>, and <inline-supplementary-material>. The elements <graphic> and <inline-graphic> contain a pointer to a still image (such as a photograph, diagram, line drawing, etc.) that is part of the document. The element <media> contains a pointer to a an non-textual object (typically a binary such as an audio clip, dataset, or animation that cannot be displayed in print) that is integral to the document’s content, where  “integral” means that the media object is discussed within (and possibly displayed within) the document; the media object is part of the document.

In contrast, the elements <supplementary-material> and <inline-supplementary-material> are used to describe both XML material (textual material such as figures, tables, and sections) and non-textual material (such as graphics, films, audio clips, datasets, or other material) that are considered to be “additional material” (non-integral) accompanying a document. Like <graphic>, <inline-graphic>, and <media>, the supplementary material elements never contain the object they describe, even if it is an XML object such as a figure, although they may point to it.

The element <inline-supplementary-material> is used to mark up references to additional material, where the reference appears within the regular flow of the text and does not have a preview image or separate caption. The <supplementary-material> element is used to describe a more complicated reference, where the description of the supplementary object resembles a figure in that it can be positioned as a floating or anchored object, may take a caption, and may use graphics or tables in the description of the object.

Content Model

<!ELEMENT  supplementary-material
                        %supplementary-material-model;               >

Expanded Content Model

((object-id)*, label?, (caption)*, (abstract)*, (kwd-group)*, (alt-text | long-desc | email | ext-link | uri)*, (disp-formula | disp-formula-group | chem-struct-wrap | disp-quote | speech | statement | verse-group | table-wrap | p | def-list | list | alternatives | array | code | graphic | media | preformat)*, (attrib | permissions)*)


The following, in order:

This element may be contained in:

<abstract>, <ack>, <alternatives>, <app>, <app-group>, <article-meta>, <bio>, <body>, <boxed-text>, <disp-quote>, <floats-group>, <front-stub>, <glossary>, <license-p>, <named-content>, <notes>, <p>, <ref-list>, <sec>, <styled-content>, <trans-abstract>

Example 1

In article metadata, naming a supplementary resource:

<contrib contrib-type="author">
<collab collab-type="committee">Accredited Standards Committee S3, 
<fpage seq="1">1</fpage>
<supplementary-material mime-subtype="zip" mimetype="application"

Example 2

In narrative text, with a caption for display:

<article dtd-version="1.1d1">
<supplementary-material id="S1" xmlns:xlink="http://www.w3.org/1999/xlink"
xlink:title="local_file" xlink:href="1471-2105-1-1-s1.pdf"
<p>Supplementary PDF file supplied by authors.</p>
<p>RNAPs seem to have arisen twice in evolution
(see the <inline-supplementary-material
xlink:title="local_file" xlink:href="timeline">
Timeline</inline-supplementary-material>. A large
family of multisubunit RNAPs includes bacterial
enzymes, archeal enzymes, eukaryotic nuclear RNAPs,
plastid-encoded chloroplast RNAPs, and RNAPs from
some eukaryotic viruses. ...</p>