<nested-kwd>

Nested Keyword

A hierarchically-structured keyword, such as a keywords from 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 on long keyword, in which the multiple constituent keywords 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 Model

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

Expanded Content Model

((kwd | compound-kwd)+, nested-kwd*)

Description

The following, in order:

This element may be contained in:

Example 1

A 3-level nested keyword list:
    ...
<kwd-group kwd-group-type="xyw-food-taxonomy">
<nested-kwd>
  <kwd>drink</kwd>
  <nested-kwd>
    <kwd>alcoholic</kwd>
    <nested-kwd>
      <kwd>beer</kwd>
      <kwd>martini</kwd>
      <kwd>wine</kwd>
    </nested-kwd>
  </nested-kwd>
  <nested-kwd>
    <kwd>dairy</kwd>
    <nested-kwd>
      <kwd>milk</kwd>
      <kwd>drinkable yogurt</kwd>
      <kwd>milkshakes</kwd>
    </nested-kwd>
  </nested-kwd>
</nested-kwd>
</kwd-group>
...   

Example 2

Nested compound keywords:
    ...
<kwd-group kwd-group-type="ISO-party-codes">
<nested-kwd>
  <compound-kwd content-type="ISO-party-codes">
    <compound-kwd-part content-type="ISO-party-code-value">4335</compound-kwd-part>
    <compound-kwd-part content-type="ISO-party-code-name">Halloween</compound-kwd-part>
  </compound-kwd>
  <nested-kwd>
    <compound-kwd>
      <compound-kwd-part content-type="ISO-party-code-value">43351</compound-kwd-part>
      <compound-kwd-part content-type="ISO-party-code-name">Adult Halloween
        Party</compound-kwd-part>
    </compound-kwd>
    <compound-kwd>
      <compound-kwd-part content-type="ISO-party-code-value">43352</compound-kwd-part>
      <compound-kwd-part content-type="ISO-party-code-name">Children's Halloween
        Party</compound-kwd-part>
    </compound-kwd>
  </nested-kwd>
</nested-kwd>
</kwd-group>
...   

Example 3

A hierarchy of heart diseases:
    ...
<kwd-group kwd-group-type="author">
  <nested-kwd>
    <kwd>Other rheumatic heart disease</kwd>
    <nested-kwd>
      <kwd>Rhematic myocarditis</kwd>
      <kwd>Other and unspecified rheumatic heart disease</kwd>
      <nested-kwd>
        <kwd>Rheumatic heart disease, unspecified</kwd>
        <kwd>Rheumatic heart failure (congestive)</kwd>
        <kwd>Other</kwd>
      </nested-kwd>
    </nested-kwd>
  </nested-kwd>
</kwd-group>
...   

Example 4

As part of section metadata:
...  
<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>  
...