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<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.

Usage/Remarks

A document may take multiple sets of keywords, with attributes such as @kwd-group-type, @specific-use, @xml:lang, or @vocab used to discriminate between the sets.
None of the individual keyword elements (<kwd>, <compound-kwd>, <nested-kwd>) may take the @xml:lang attribute; that is reserved for the <kwd-group>. This means that keywords must be separated by language and placed into language groups.
Typically, the @kwd-group-type attribute 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 <kwd-group> contains terms from a single controlled vocabulary (ontology, taxonomy, term-list, vocabulary, industry glossary, or other known source), the two vocabulary identification attributes should be used to record that source.
Vocabulary Identification Attributes
Two attributes are used in this Tag Set to identify a vocabulary. When these attributes are used on a <kwd-group>, they apply to all keywords in the group and need not be repeated on each <kwd> or other enclosed element.
vocab
Name of the controlled or uncontrolled vocabulary, taxonomy, ontology, index, database, or similar that is the source of a term. For example, the 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
assigning-authority
kwd-group-type
specific-use
vocab
vocab-identifier

Base Attributes

id
xml:base
xml:lang
Models and Context
May be contained in
<article-meta>, <sec-meta>
Description
The following, in order:
Content Model
<!ELEMENT  kwd-group    %kwd-group-model;                            >
Expanded Content Model

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

Tagged Samples
Author’s keywords 
<article dtd-version="1.3">
 <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>
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>
...
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>
...
One <kwd-group>, Two vocabularies 
...
<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>
...
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>
...
Dublin Core 
...
<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>
...
With vocabulary attributes 
...
<kwd-group kwd-group-type="physh" xml:lang="en"
  vocab="PhySH" vocab-identifier="https://physh.org/">
 <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>
...
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