<kwd>

Keyword

A keyword is a finding aid used to record one subject term, key phrase, abbreviation, indexing word, taxonomic structure, or other expression that is associated with the whole structure (such as an article). Keywords can be used for identification, searching, and indexing purposes. A keyword element (<kwd>) may contain a repetition of words found in the structure or it may contain broader terms, narrower terms, related terms, or taxonomic identifiers used to find the structure in a search or provide semantic classification of the text by mapping a specific structure to a taxonomy.

Remarks

Keywords are contained in <kwd-group>s. There may be several <kwd-group>s, each of which can be identified separately by language, vocabulary, or taxonomy source. None of the individual keyword elements (<kwd>, <compound-kwd>, <nested-kwd>) take the @xml:lang attribute; that is reserved for the <kwd-group>. This means that keywords must be sorted by language and entered in language groups.
Related Essay: For a discussion on the use of <kwd>, see Keywords.

Related Elements

This Tag Set contains several differently-structured types of keywords:
  • <kwd> is used with simple keywords: words or phrases.
  • <compound-kwd> is used with multi-part keywords, such as a keyword that is a code-and-term pair.
  • <nested-kwd> is used with hierarchical keywords structures, such as taxonomies, to record a portion of a taxonomic hierarchy. Both simple and compound keywords can be nested hierarchically.
  • <unstructured-kwd-group> is used to hold one long keyword string, which contains multiple constituent keywords that are not tagged individually.
Best Practice: In this Tag Set, nested keywords (<nested-kwd>) should be reserved for hierarchical material such as taxonomies. There are a few journal tag sets in which keyword nesting is used to simulate a two-part list. Such a keyword list should be tagged as a <def-list> instead.

Attributes

content-type Type of Content
id Document Internal Identifier
xml:base Base

Content Model

<!ELEMENT  kwd          (#PCDATA %kwd-elements;)*                    >

Expanded Content Model

(#PCDATA | email | ext-link | uri | inline-supplementary-material | related-article | related-object | hr | bold | fixed-case | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | ruby | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x | break)*

Description

This element may be contained in:

Example 1

An author’s list of keywords for a document:
<article dtd-version="1.1d2">
<front>
...
<abstract>...</abstract>
<kwd-group kwd-group-type="author">
<kwd>DNA analysis</kwd>
<kwd>gene expression</kwd>
<kwd>parallel cloning</kwd>
<kwd>fluid microarray</kwd>
</kwd-group>
</article-meta>
</front>
...</article>

Example 2

Multiple keyword groups for a document, including those created by Inspec:
...
<article-meta>
...  
<kwd-group kwd-group-type="Inspec">
<kwd>diversity reception</kwd>
<kwd>Doppler radar</kwd>
<kwd>Doppler shift</kwd>
<kwd>encoding</kwd>
<kwd>optimisation</kwd>
<kwd>orthogonal codes</kwd>
<kwd>radar signal processing</kwd>
<kwd>MIMO radar</kwd>
</kwd-group>

<kwd-group kwd-group-type="uncontrolled">
<kwd>polyphase codes optimisation</kwd>
<kwd>multiinput-multioutput radars</kwd>
<kwd>radar performance</kwd>
<kwd>diversity technique</kwd>
<kwd>MIMO radar transmission</kwd>
<kwd>diversity performance</kwd>
<kwd>orthogonal codes</kwd>
<kwd>Doppler sensitive</kwd>
<kwd>side-lobes level</kwd>
<kwd>adaptive clonal selection algorithm</kwd>
<kwd>polyphase coded orthogonal signals</kwd>
<kwd>aperiodic autocorrelation side lobe</kwd>
<kwd>Doppler shift tolerance</kwd>
<kwd>sustainable Doppler shifts</kwd>
<kwd>Doppler tolerance performances</kwd>
</kwd-group>

<kwd-group kwd-group-type="Inspec-class">
<compound-kwd>
<compound-kwd-part content-type="code">B0260</compound-kwd-part>
<compound-kwd-part content-type="text">Optimisation 
techniques</compound-kwd-part>
</compound-kwd>
<compound-kwd>
<compound-kwd-part content-type="code">B6140</compound-kwd-part>
<compound-kwd-part content-type="text">Signal processing and detection</compound-kwd-part>
</compound-kwd>
<compound-kwd>
<compound-kwd-part content-type="code">B6320</compound-kwd-part>
<compound-kwd-part content-type="text">Radar equipment, systems 
and applications</compound-kwd-part>
</compound-kwd>
</kwd-group>
</article-meta>
...

Example 3

Multiple keyword groups for a document (including Japanese):
...
<article-meta>
...  
<kwd-group xml:lang="en">
<kwd>heated air</kwd>
</kwd-group>

<kwd-group xml:lang="ja">
<kwd>加温空気</kwd>
</kwd-group>
...  
</article-meta>
...

Example 4

App Navigation Information:
...
<sec>
<sec-meta>
<kwd-group specific-use="mobile-nav">
  <nested-kwd>
    <kwd>dosing</kwd>
    <nested-kwd>
      <kwd>geriatric</kwd>
      <nested-kwd>
        <kwd>Digoxin</kwd>
      </nested-kwd>
    </nested-kwd>
  </nested-kwd>
</kwd-group>
  
<kwd-group specific-use="mobile-nav">
  <nested-kwd>
    <kwd>Digoxin</kwd>
    <nested-kwd>
      <kwd>dosing</kwd>
      <nested-kwd>
        <kwd>geriatric</kwd>
      </nested-kwd>
    </nested-kwd>
  </nested-kwd>
</kwd-group>
</sec-meta>
<title>Dosing Table, Geriatric</title>
...
</sec>
...