<nested-kwd>

Nested Keyword

A hierarchically-structured keyword, such as a keywords from a controlled vocabulary.

Remarks

Key words 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.
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 Essay: For a discussion on the use of <kwd>, see Keywords.

Related Elements

This Tag Set contains several differently-structured types of keywords:
  • The element <kwd> is used with simple keywords: words or phrases.
  • The element <compound-kwd> is used with multi-part keywords, such as a keyword that is a code-and-term pair.
  • The element <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.

Attributes

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  nested-kwd   %nested-kwd-model;                           >

Expanded Content Model

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

Description

The following, in order:

This element may be contained in:

<kwd-group>, <nested-kwd>

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>
...

Article Authoring Tag Library NISO JATS Version 1.2 (ANSI/NISO Z39.96-2019)

Version of May 2019

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