<kwd-group>

Keyword Group

Container element for one set of keywords (such as <kwd>s, <nested-kwd>s, or <compound-kwd>s) used to describe a document.

Remarks

Related Resource: For a discussion on the use of <kwd-group>, see Keywords.
Usage: A document may take multiple sets of keywords, with the @kwd-group-type, @specific-use, or @xml:lang attributes used to discriminate between them. The <kwd> element does not 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.
The @kwd-group-type attribute most commonly names the source of the keywords, such as “mesh”, “ISO-463”, or “author-generated”. But it is also appropriate to use @kwd-group-type to identify the type of keywords, for example, “hierarchical” for keywords that are grouped into a hierarchy, “abbreviations” for keywords that contain an abbreviation and its expansion, or “code” for keywords that contain a code and its text but where the source of the codes is unknown.
Attribute Best Practice: If the content of the <kwd-group> 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 record that source. The source named can be a formal ontology or an informal field of study. Two attributes are used in this Tag Set to identify such a controlled or uncontrolled vocabulary:
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/”.

Attributes

Content Model

<!ELEMENT  kwd-group    %kwd-group-model;                            >

Expanded Content Model

(title?, (kwd | compound-kwd | nested-kwd)+)

Description

The following, in order:

This element may be contained in:

Example 1

An author’s list of keywords for a document:
<article dtd-version="1.3d1">
<front>
<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>
</front>
...
</article>

Example 2

Keyword group with compound keywords:
... 
<kwd-group> 
<compound-kwd>
<compound-kwd-part content-type="code">B01D57/02</compound-kwd-part>
<compound-kwd-part content-type="value">By electrophoresis</compound-kwd-part>
</compound-kwd>
...
</kwd-group>
...

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

Two vocabularies in one keyword group:
...
<kwd-group kwd-group-type="library-classifications">
  <compound-kwd vocab="LOC" 
      vocab-term="Diseases of the respiratory system"
      vocab-term-identifier="RC705-779">
    <compound-kwd-part>RC705-779</compound-kwd-part>
    <compound-kwd-part>Diseases of the respiratory system</compound-kwd-part>
  </compound-kwd>

  <compound-kwd vocab="Dewey Decimal" 
      vocab-term="Diseases of the respiratory system"
      vocab-term-identifier="616.3">
    <compound-kwd-part>616.3</compound-kwd-part>
    <compound-kwd-part>Diseases of the respiratory system</compound-kwd-part>
  </compound-kwd>
</kwd-group>
...

Example 5

An ICD10 vocabulary:
  
...
<kwd-group kwd-group-type="conditions">
  <compound-kwd vocab="ICD10" vocab-term="J00-J99">
    <compound-kwd-part>J00-J99</compound-kwd-part>
    <compound-kwd-part>Diseases of the respiratory system</compound-kwd-part>
  </compound-kwd>
</kwd-group>
...

  

Example 6

Generic subject within Dublin Core subjects:
...
<kwd-group vocab="dublincore" kwd-group-type="classification">
  <nested-kwd vocab="scientific name">
    <kwd vocab="scientific name" vocab-term="kingdom">Plantae</kwd>
    <kwd vocab="scientific name" vocab-term="phylum">Anthophyta</kwd>
    <kwd vocab="scientific name" vocab-term="class">Monocoty</kwd>
    <kwd vocab="scientific name" vocab-term="order">Commelinales</kwd>
    <kwd vocab="scientific name" vocab-term="family">Poaceae</kwd>
    <kwd vocab="scientific name" vocab-term="genus">Zea</kwd>
    <kwd vocab="scientific name" vocab-term="species">Z. mays</kwd>
  </nested-kwd>
</kwd-group>
...

Example 7

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>
...