<ext-link> External Link

Link to an external file or resource.


Linking Best Practice

Use the standard XLink attributes to provide a live link to the external source. The attribute @xlink:href is not required, but should be used to provide the link.
Resource Type
The @ext-link-type attribute can be used to give an indication of the type of resource to which the external link points. While this Tag Set does not constrain the values of this attribute, and ordinary text is acceptable, the values include the following and similar:
Digital Object Identifier
File transfer protocol
Website or web service
Enzyme nomenclature (See: http://www.chem.qmw.ac.uk/iubmb/enzyme/)
GenBank identifier
Protein data bank (See: http://www.rcsb.org/pdb/)
Protein Information Resource (See: http://pir.georgetown.edu)
Related Elements
Several elements in this Tag Set related to URNs, URIs, and external linking.
  • The element <ext-link> should be used to create a link to an external resource.
  • The element <uri> wraps a URI reference in text that might not be an external link.
  • The element <self-uri> is used to hold the URI/URN/URL of a version of this standards document.
  • The element <urn> is a holdover from ISO STS, used only in ISO-related metadata elements.

Base Attributes

Linking Attributes

xlink:type (fixed value = simple)


xmlns:xlink (fixed value = http://www.w3.org/1999/xlink)
Models and Context
May be contained in
Content Model
<!ELEMENT  ext-link     (#PCDATA %ext-link-elements;)*               >
Expanded Content Model

(#PCDATA | bold | fixed-case | italic | monospace | num | overline | roman | sans-serif | sc | strike | underline | ruby | inline-graphic | private-char | inline-code | inline-media | named-content | styled-content | sub | sup)*

Tagged Samples
Within text
 <p>Comments, suggestions, or questions on this document 
  should be addressed to the Defense Standardization Program 
  Office (<abbrev>DSPO</abbrev>), 8725 John J. Kingman Road, 
  Stop 5100, Fort Belvoir, VA 22060-6220 or emailed to 
  <email>DSPO@dla.mil</email>. Since contact information 
  can change, you may want to verify the currency of this 
  address information using the ASSIST Online database at 
  <ext-link xlink:href="https://assist.dla.mil"
<p>Terms to describe Personal Factors can be found in 
the <italic>Systematized Nomenclature of Medicine &mdash; 
Clinical Terms</italic> (<abbrev>SNOMED-CT</abbrev>), available 
at: <ext-link xlink:href="http://www.ihtsdo.org/snomed-ct/"
In mixed-style bibliographic reference (punctuation and spacing preserved)
<ref id="bibr40">
  ><person-group><collab>World Health Organization</collab>, 
   <collab>World Bank</collab></person-group>. 
  <year iso-8601-date="2011">2011</year>), 
  <source>World Report on Disability</source>, 
  available at: <ext-link ext-link-type="uri"