Supplementary Material


Additional data files that contain information directly supportive of the document, for example, an audio clip, movie, database, spreadsheet, applet, or other external file.

This element has a similar function to the audiovisual element in some DTDs and the unprinted-item element (used only for electronic files) in other DTDs.


The element is used in two senses: first, inside the article front matter as an alert to the existence of supplementary material; and second, as part of the textual flow, where it is similar to a Figure, in that it can be positioned as a floating or anchored object and may take a caption. In addition, the <supplementary-material> element may identify its file type with the mimetype attribute.

The position attribute may be used to indicate whether this element must be anchored at its exact location within the text or whether it may float, for example, to the top of the next page, into the next column, to the end of a logical file, or within a separate window.

Authoring Note: Supplementary Material may contain a preview image (e.g., the first frame of a movie, tagged as a <graphic>), with the caption/preview placed in a manner similar to a Figure and a cross-reference made to the material from the text.


alternate-form-of Alternate Form of Graphic, Media Object, Etc.
content-type Type of Named Content
id Identifier
mime-subtype Mime Subtype
mimetype Mime Type
position Position
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
xml:lang Language
xmlns:xlink XLink Namespace Declaration

Related Elements

This DTD Suite contains several elements to describe non-XML material: <graphic>, <inline-graphic>, <media>, and <supplementary-material>. The elements <graphic> and <inline-graphic> are used for “still” images, i.e., photographs, diagrams, etc. The distinction between the two other elements is more subtle. The element <media> should be used for movies, audio clips, or media in other formats which is intrinsic to the document’s content, that is, the media object is discussed within the document. The element <supplementary-material> should be used for films, audio clips, or other material which enhances a document, but which is not discussed as part of the document.

See <inline-supplementary-material> for a simpler form that can be used to mark up text references to supplementary material where the reference appears in the regular flow of the text and does not have a preview image or separate caption.

Model Description

The following, in order:

Tagged Example

<title>Supplemental Material</title>
<p>Movie clips to supplement this article are available
online at <ext-link ext-link-type="uri">radiographics.rsnajnls.org/cgi/content/full/21/4/943/DC1
<p>Anterior fontanelle imaging has traditionally
been the mainstay of neonatal cranial ultrasonography
(US). However, this traditional approach has limited
diagnostic accuracy, ...</p>...