<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 a 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 associated with a 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 separated by language and entered in language groups.
Related Resource: For a discussion on the use of <kwd>, see Keywords.
Best Practice: In this Tag Set, nested keywords (<nested-kwd>) should be reserved for hierarchical material such as taxonomies. There are a few journal/book 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.
Attribute Best Practice: If the content of the <kwd> element is a term from a controlled vocabulary (ontology, taxonomy, term-list, vocabulary, industry glossary, or other known source), the vocabulary attributes should be used to identify that source. The source named can be a formal ontology or an informal field of study.
Term Identification Attributes: Two attributes are used in this Tag Set to identify an individual term from a vocabulary (controlled or an uncontrolled):
vocab-term
The content of the element is the display version of the vocabulary or taxonomic term. The @vocab-term attribute holds the canonical version of the same term, as it appears in the vocabulary. For example, if the attribute value is “digitized-vor”, the element might contain the display text “Digitized Version of Record”.
vocab-term-identifier
Unique identifier of the term within a specific vocabulary, such as (but not limited to) an item number, a URI, DOI, etc.
Vocabulary Identification Attributes: Two attributes are used in this Tag Set to identify a vocabulary. If these attributes have already been used on <kwd-group>, they need not be repeated on each <kwd>.
vocab
Name of the controlled or uncontrolled vocabulary, taxonomy, ontology, index, database, or similar that is the source of the term. For example, for a subject term, a value might be the IPC Codes (“ipc”) or MESH headings (“mesh”). For an uncontrolled term, the value might be an area of study such as “medical-devices” or merely the word “uncontrolled”.
vocab-identifier
Unique identifier of the vocabulary, such as (but not limited to) a URI or DOI. For example, for Dublin Core (DCC), the identifier may be “http://dublincore.org/documents/2012/06/14/dces/”.

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

assigning-authority Authority Responsible for an Identifier
content-type Type of Content
id Document Internal Identifier
vocab Vocabulary/Taxonomy Name
vocab-identifier Vocabulary/Taxonomy Identifier
vocab-term Vocabulary/Taxonomy Term
vocab-term-identifier Vocabulary/Taxonomy Term 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 | inline-media | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x | break)*

Description

Any combination of:

This element may be contained in:

<kwd-group>, <nested-kwd>

Example 1

An author’s list of keywords for a document:
...
<article-meta>
...
<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>
...

Example 2

Multiple keyword groups for a document, where each group was created by a separate organization or process:
...
<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

Nested keyword in section metadata to provide navigation information for an app:
...
<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>
...

Example 5

Keywords with vocabulary and vocabulary-term identifiers:
...
<kwd-group kwd-group-type="physh" vocab="PhySH" vocab-identifier="https://physh.org/" xml:lang="en">
 <nested-kwd>
   <kwd content-type="facet" 
     vocab="PhySH"  vocab-identifier="https://physh.org/" 
     vocab-term-identifier=
     "https://physh.aps.org/browse?facetIds=Research%2520Areas"
   >Research Areas</kwd>
   <nested-kwd>
     <kwd content-type="concept" 
       vocab="PhySH"  vocab-identifier="https://physh.org/"
       vocab-term-identifier=
       "https://doi.org/10.29172/ba7ccb8ed7eb4e6f9c1eb622f5b4e242"
     >Atomic &amp; molecular processes in external fields</kwd>
     <nested-kwd>
       <kwd content-type="concept" 
         vocab="PhySH"  vocab-identifier="https://physh.org/"
         vocab-term-identifier=
           "https://doi.org/10.29172/da893accf204480b8a7e386479c50687"
       >Coherent control</kwd>
     </nested-kwd>
   </nested-kwd>
 </nested-kwd>
 <nested-kwd>
   <kwd content-type="facet" 
     vocab="PhySH"  vocab-identifier="https://physh.org/"
     vocab-term-identifier=
       "https://physh.aps.org/browse?facetIds=Physical%2520Systems"
   >Physical Systems</kwd>
   <nested-kwd>
     <kwd content-type="concept" 
       vocab="PhySH"  vocab-identifier="https://physh.org/"
       vocab-term-identifier=
        "https://doi.org/10.29172/bd252d88a60848979416daf84dee7f6b"
     >Atomic Systems</kwd>
     <nested-kwd>
       <kwd content-type="concept" 
         vocab="PhySH"  vocab-identifier="https://physh.org/"
         vocab-term-identifier=
          "https://doi.org/10.29172/42e66168abfd4328aa9df6fc3a077f75"
       >Molecules</kwd>
     </nested-kwd>
   </nested-kwd>
 </nested-kwd>
</kwd-group>
...

Journal Archiving and Interchange Tag Library NISO JATS Version 1.3d1 (ANSI/NISO Z39.96-2019)

Version of October 2019

Back to Top