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Citation Details

Abbreviated Citations
Some citations are complicated by the fact that they do not provide the full citation information for each cited reference. For example, some journals identify successive bibliographic references by the same author or involving the same journal by omitting the duplicated portion of the reference and inserting a vertical rule, the word “Ibid”, the word “Id.”, etc. Other publishers routinely omit the title of a cited journal article to save space. While Best practice is to tag all citations completely, archives or publishers may choose to tag an abbreviated citation exactly as it was displayed.
If it is important for an archive or publisher to make each citation accessible for citation matching services, incomplete references should be enhanced by tagging the missing information based on the preceding reference. At the discretion of the archive, the word “Ibid” or “Id.” may also be retained as part of the textual content.
As an example, here is a citation that mixes multiple works by a single author: 
Holmes, S. J. (1) Phototaxis in the amphipoda. Am. Jour. 
Physiol., 5, 211, 1901; (2) The reactions of Ranatra to 
light. Jour. Comp. Neur. Psych., 15, 305, 1905.
To preserve the exact order and punctuation of these citations, each publisher or archive must decide whether the semicolon and space between the citations is part of the first citation or the second. Here is the double-citation reference tagged as a mixed-style citation, with the punctuation added to the end of the first citation: 
<ref id="ref1" content-type="double-author">
 <mixed-citation publication-type="journal">
  <string-name><surname>Holmes</surname>, <given-names>S. J.</given-names>
  </string-name> <label>(1)</label> <article-title>Phototaxis
  in the amphipoda</article-title>. <source>Am. Jour. 
  Physiol.</source>, <volume>5</volume>, <issue>211
  </issue>, <year iso-8601-date="1901">1901</year>; 
 </mixed-citation>
 <mixed-citation><label>(2)</label> <article-title>The 
  reactions of Ranatra to light</article-title>. <source>Jour.
  Comp. Neur. Psych.</source>, <volume>15</volume>, 
  <issue>305</issue>, <year iso-8601-date="1905">1905</year>.
 </mixed-citation>
</ref>
If completeness of citations for reference matching is more important than preserving the original word order and exact punctuation, information that is only displayed in one citation should be tagged in both. Because display is less important than completeness, the label can be moved to the beginning of the citation. Here is the same citation tagged as an element-style citation and incorporating the changes just mentioned: 
<ref id="ref1" content-type="double-author">
 <element-citation publication-type="journal">
  <label>(1)</label>
  <name><surname>Holmes</surname><given-names>S. J.</given-names></name>
  <article-title>Phototaxis in the amphipoda</article-title>
  <source>Am. Jour. Physiol.</source>
  <volume>5</volume>
  <issue>211</issue>
  <year iso-8601-date="1901">1901</year>
 </element-citation>
 <element-citation>
  <label>(2)</label>
  <name><surname>Holmes</surname><given-names>S.J.</given-names></name>
  <article-title>The reactions of Ranatra to light</article-title>
  <source>Jour. Comp. Neur. Psych.</source>
  <volume>15</volume>
  <issue>305</issue>
  <year iso-8601-date="1905">1905</year>
 </element-citation>
</ref>
Dates in Citations
Several kinds of dates can be identified within the citation elements <element-citation> and <mixed-citation>:
  • the publication date of the cited resource,
  • the date(s) on which a conference was held, and
  • all other dates mentioned in the citation, such as access dates, patent application dates, time stamps, etc.
It is Best practice to tag the publication date, which can be recorded using ordinary date tags such as <year>. Several of the date elements may be used in a citation, including <day>, <month>, and <season>. Typically, for cited journal articles, the citation will contain only a <year>: <year>2008</year>.
All other dates in the citations, if they are tagged, use the <date-in-citation> element, identifying the type of date with the @content-type attribute. For example, if the resource has a time stamp when it was posted (in addition to the regular publication date), the time stamp can be recorded as: <date-in-citation content-type="time-stamp"/>...</date-in-citation>.
Publication Date
Within bibliographic references (<element-citation> and <mixed-citation>), the most important date to tag for purposes of searching and making the citation into a live link is the publication date. The most common form of the date is the year (<year>), shown in the following citation which also includes the month: 
<mixed-citation publication-type="journal" publication-format="print">
 <name>...</name>. <article-title>Links between dietary salt ... and cardiovascular diseases</article-title>. <source>Physiol Rev</source>. <year iso-8601-date="2005-04">2005</year> <month>Apr</month>;<volume>85</volume>
 (<issue>2</issue>):<fpage>679</fpage>-<lpage>715</lpage>.
</mixed-citation>
Multiple years may be tagged with separate <year> elements: 
<mixed-citation publication-type="journal">...
 <year iso-8601-date="2008">2008</year>&ndash;<year>2009</year>;  
 ...</mixed-citation>
or combined into a single year:
<mixed-citation publication-type="journal">...
 <year iso-8601-date="2008">2008&ndash;2009</year>; 
 ...</mixed-citation>
In this Tag Set, the elements <date>, <day>, <month>, and <season> may all be used in addition to <year> to describe the publication date: 
<element-citation publication-type="book">...
 <season>Winter</season><year iso-8601-date="2008">2008</year>
 ...</element-citation>

<mixed-citation publication-type="book">... 
 <season>Winter</season> <year iso-8601-date="2008">2008</year> 
 ...</mixed-citation>
Non-publication Dates
Within bibliographic citations (<element-citation> and <mixed-citation>), the <date-in-citation> element can be used to tag dates other than the publication date of the cited source, for example, the copyright date, the date on which the contributor accessed the source, the date the cited resource was withdrawn, or a time stamp indicating when the work was published, for continuously or frequently updated works. The @content-type attribute should be used to identify the purpose or type of date; for example, if the element contains the date on which the article was withdrawn, the value of the @content-type would be “withdrawn”.
Here is an example in which <date-in-citation> was used to record the date on which the cited work was last updated. If a resource has a time stamp in addition to a publication date, that time stamp could be recorded using this element with a @content-type attribute of “time-stamp”. Such a time stamp is applied to the resource by its creators, usually as a version indicator, and says nothing about when a contributor examined the resource, only what version was found at the time of examination. Some online resources are changing so quickly that a citation to the resource is not complete without the publication time of the resource. The @content-type should be used to identify such time-stamps: 
<element-citation>... 
 <date-in-citation content-type="time-stamp" iso-8601-date="2014-01-11T11:57:00-5:00">
  January 11, 2014 at 11:57am</date-in-citation> 
 ...</element-citation>
<mixed-citation>... 
 <date-in-citation content-type="time-stamp" iso-8601-date="2014-01-11T11:57:00-5:00">
 January 11, 2014 at 11:57am</date-in-citation> 
 ...</mixed-citation>
Here is an example of the <date-in-citation> element used to record publication history dates that were noted in the citation: 
<element-citation publication-type="book" publication-format="web">
 <collab-name>CENDI Copyright Working Group</collab-name>
 <source>Frequently asked questions about copyright ...</source>
 <comment>[Internet]</comment>
 <person-group person-group-type="editor">...</person-group>
 ...<year iso-8601-date="2004-08">2004</year>
 <month>Aug</month>
 <date-in-citation iso-8601-date="2006-09-02">modified 2006 Sep 2</date-in-citation>
 <date-in-citation iso-8601-date="2006-11-06">cited 2006 Nov 6</date-in-citation>
 ...</element-citation>

<mixed-citation publication-type="book" publication-format="web">
 <collab-name>CENDI Copyright Working Group</collab-name>. <source>Frequently 
 asked questions about copyright: ...</source>  [Internet].
 <person-group person-group-type="editor">...</person-group>, editors.
 ... <year iso-8601-date="2004-08">2004</year> <month>Aug</month>
 [<date-in-citation iso-8601-date="2006-09-02">modified 2006 Sep 2</date-in-citation>;
 <date-in-citation iso-8601-date="2006-11-06">cited 2006 Nov 6</date-in-citation>]. 
 ...</mixed-citation>
Unlike the <year> element as used in a publication date where Best practice is to tag multiple years with multiple elements, multiple years in non-publication dates should be tagged in a single element: 
<date-in-citation content-type="copyright" iso-8601-date="2004">2004
 &ndash;2009</date-in-citation>
In a <mixed-citation>, the above date can be tagged as: 
Copyright <date-in-citation content-type="copyright">2004-2009</date-in-citation>
In an <element-citation>, the same date could be tagged as follows or the word “Copyright” could be generated for display: 
...
<comment>Copyright</comment>
<date-in-citation content-type="copyright" iso-8601-date="2004">2004-2009</date-in-citation>
...
Date Prefixes and Suffixes
Some citation dates are prefixed with one or more letters. Some publishers prefix the year with a copyright symbol or a lower case “c” meaning that this is a copyright date. In mixed-style citations, these symbols can be preserved directly in the text, between tagged elements: 
<mixed-citation publication-type="book">... 
 &copy;<year content-type="copyright" iso-8601-date="2004">2004</year>; 
 ...</mixed-citation>

<mixed-citation publication-type="book">... 
 c<year content-type="copyright" iso-8601-date="2004">2004</year>; 
 ...</mixed-citation>
In an element-only style citation, the symbol or the letter should either be removed entirely and left for the display to infer from the @content-type="copyright" or placed into a <comment> element. 
<element-citation publication-type="book">
 ... 
 <comment>&copy;</comment><year content-type="copyright" iso-8601-date="2004">2004</year>
 ...</element-citation>

<element-citation publication-type="book">... 
 <year content-type="copyright" iso-8601-date="2004">2004</year>
 ...</element-citation>
In some books or older manuscripts, the lower case “c” could also stand for “circa”, meaning approximate. Similar information might be indicated by the prefix or suffix “approx.” or the prefix “between”. Such terms should be preserved similarly; they should be left in the text for mixed citations and placed in comments for element citations.
Labels in Citations
Some bibliographic reference lists are unnumbered, some are bulleted lists, some have a counting number before each reference, and some have special symbols or author-descriptive labels (such as [Piez 2009]) constructed according to “Harvard rules” or other semantic numbering system. The first decision a publisher or archive needs to make is whether to capture such numbers using <label> or whether all such designators are generated for display or print. A repository archive may choose to preserve all numbers; a publisher may choose to generate them.
Assuming numbers will be preserved, the next decision concerns punctuation and spacing. It is possible to preserve all punctuation and spacing “3.” or “[Lapeyre-Usdin 2009]” or to preserve just the significant portion of the label (the numeral or the name-year) and not preserve the spacing or punctuation: “3” or “Lapeyre-Usdin 2009”.
Usually the label applies to the reference (<ref>). Citations (<element-citation> or <mixed-citation>) are typically only numbered when multiple citations occur within a single reference. In such cases, the reference is typically numbered in series with the other, single references, and the citations are numbered using a different numbering scheme. For example, a reference numbered <label>4.</label> could have citations inside it labeled “a.”, “b.”, “c.”; or “[Gaylord 2005]”, “[Beck 2006]”, “[Usdin 2009]”.
Language of Cited Material
The language of cited material can be identified using the @hreflang attribute on the citation element (<mixed-citation> or <element-citation>). The attribute @hreflang names the language of the document being cited, rather then the language in which the citation is written.
It is recommended practice to use @hreflang to name the language of material being cited. Some publishers also insert a phrase in the text to indicate the language of the cited material (for example, “In Japanese”) to ensure that target-language information is displayed as part of the citation. Such a phrase might appear in the text of a mixed citation (<mixed-citation>) or within a <comment> in an element citation (<comment>In Japanese<comment>). Even if a textual display is tagged, it is still recommended practice to provide the @hreflang attribute on the citation, as it is machine processable.
Length and Size
This Tag Set has a single general purpose element <size> for recording the number of pages in a book, the showing time of a film, the number of kilo/mega/tera-bytes in a dataset, or any other measurement of size, length, or extent that may be recorded for a cited work.
The @units attribute must be used to state the units of measure, such as “pages”, “minutes”, “paragraphs”, “MB”, etc. A units value is typically given in the plural (“pages” not “page”).
<page-count> is a metadata element in the description of the work that records similar page-size information for the work rather than for cited material. The <size> and <page-count> elements are modeled very differently. The size element is assumed to contain the textual value of the size: 
<size units="paragraphs">8</size>
while the page count element is an EMPTY element that stores its value in the @count attribute: 
<page-count count="26"/>
In element-style citations (<element-citation>), displaying the units can be handled in the following ways:
  • If the @units attribute value has been tagged consistently, the text can be generated on display and does not have to be included in the element content: 
    <size units="pages">256</size>
  • If the publisher or archive does not wish to generate text based on the attribute or the attributes have not been tagged consistently, the text can be included as content in the <size> tag: 
    <size units="pages">256 pages</size>
Ordinal Numbers
Cited Edition Statements: Edition statements (<edition>) in JATS journal articles are allowed only within citations (<mixed-citation> or <element-citation>), not in the metadata for the article (<article-meta>). Edition statements inside citations are frequently given as ordinal numbers (first, second, third) and abbreviated with an “st”, “th”, or “rd” suffix. These ordinals may either directly follow the number (4th) or be placed in a superscript following the number (4<sup>th</sup>). JATS allows some flexibility in placing these ordinals, and each publisher or archive will need to decide whether or not these ordinal suffixes are part of the element’s content.
For example, consider the citation that names the edition as “3rd”:
  • Archives and publishers who wish to regularize content for searching can eliminate these extra characters and tag the edition as <edition>3<edition>.
  • Archives who wish to record exactly each detail of the printed volume can retain these extra characters:
    • inside the edition statement: <edition>3<sup>rd</sup><edition>
    • outside the edition statement inside the text of a mixed citation: <edition>3<edition><sup>rd</sup>
    • inside the edition statement, using the @designator attribute to preserve just the number: 
      ...
<edition designator="3">3<sup>rd</sup></edition>
...
Volume Numbers: In JATS journal articles, the volume number element (<volume>) is used both inside the article metadata and inside citations:
  • Inside the article metadata (<article-meta>), the ordinals for a volume number must be placed inside the <volume> element.
  • Inside citations (<mixed-citation> or <element-citation>), the ordinals used with a volume number can be:
    • inside the volume number: <volume>1<sup>st</sup><volume>
    • outside the volume number inside the text of a mixed citation: <volume>1<volume><sup>st</sup>
The related <volume-id> element is used to record an identifier, such as a DOI, that describes an entire volume of a journal or series.
Personal Names in Citations
For material on the uses of <name> and <string-name> in all types of citations, see Names and String Names in Citations that is part of the section on Personal Names.
Titles in Citations
The title of a work may be the most critical component of a citation, and JATS uses a variety of elements to capture different types of titles, rather than a single “title” element. There can be hierarchies of titles, and different elements are used to tag the various levels of hierarchy. For example, a journal (top-level) contains an article (sub-level). This would be tagged:

Title of the Cited Resource (<source>)

Within a bibliographic reference (<mixed-citation> or <element-citation> and similar elements such as <related-article> and <product>), the top-most title in the citation is the <source> element, which names the title of the resource being referenced. For example, a <source> element might contain:
  • the name of a journal;
  • a book title;
  • the name of podcast;
  • a report title;
  • a conference proceedings title;
  • the name of an audio, television, radio, or streaming program;
  • the name of a software product (“Oxygen Editor”, “Microsoft Excel”);
  • the “name” of a website;
  • for data citations, the name of the top-hierarchical level of a data repository; or
  • the name or title of any resource being cited (patent, standard, thesis, working paper, etc.).
Here the <source> is the title of a report: 
<mixed-citation publication-type="report" publisher-type="government">
  <collab-name>Federal Highway Administration</collab-name> (FHWA). 
  (<year iso-8601-date="1992">1992</year>). “<article-title>Evaluating 
  scour at bridges</article-title>.” <source>Hydr. Engrg.
  Circular No.  18</source>: <gov>FHWA-IP-90-017</gov>, 
  <institution>Office of Engineering, Bridge Div.</institution>, Washington, 
  D.C.</mixed-citation>
When a citation names two or more titles in different languages, the title should be repeated with the @xml:lang attribute to identify the language of the title and the multi-language attributes can describe the relationship between the two titles and/or the origin of the titles. For example, if a book was originally published in German and then translated into English, one <source> element might contain the German title, and a second <source> element contain the equivalent English title. The multi-language attributes could flag the German title as original from the author and the English title as a translation, also from the author. (Note: The element <trans-source> has been deprecated and should not be used.)

Not Just <article-title>s

The hierarchical level just below the resource names the part of the resource being cited (for example, the title of the article within the journal). These second-level titles are tagged differently depending on the type or resource being cited.
For example:
  • For journal citations, the <source> is the name of the journal, and the title of the article being cited is <article-title>.
  • For preprint citations, the title of the preprint is <article-title>.
  • For book citations, <source> is the name of the book, and <part-title> is the title of a book chapter, module, lesson, part, or other-named book division that is being cited. (Note: the deprecated element <chapter-title> was used for this in past versions of JATS.)
  • For citing a specific episode or similar of a podcast, streaming show, radio broadcast, cable show, television news, etc., the name of the show, podcast, etc. is the <source>, and a <part-title> names the episode cited. For example: <part-title>The Beetle Whisperer</part-title>, <source>All Thing Considered</source>.
  • For citing data sources, the name of the data repository is usually tagged as a <source>, but it may also be tagged as a <data-title>. A data citation may use as many <data-title> elements as necessary to name the multiple levels of a hierarchical data source.
  • For citing a standalone audio/video/multimedia/podcast, the “title” of the work will typically be thought of as the <source> rather than as any of the title elements, e.g., <source>How to build and fire a mini-cannon</source>. If the audio/video/multimedia/podcast is part of a series, the series name should be the <source>, and the episode title should be a <part-title>.
  • For citing a video within a journal, if the citation type is “video”, the journal name would be the <source>, and the title of the video would be tagged as a <part-title>.
Here the <part-title> is the title of a chapter in a book: 
<mixed-citation publication-type="book" publication-format="print">
  <string-name><surname>Al-Ibrahim</surname>,
  <given-names>MS</given-names></string-name>,
  <string-name><surname>Gross</surname>,
  <given-names>JY</given-names></string-name>.
  <part-title>Tobacco use</part-title>.
  <source>Clinical methods: the history, 
  physical, and laboratory examinations</source>.
  <publisher-loc>Stoneham (MA)</publisher-loc>:
  <publisher-name>Butterworth Publishers</publisher-name>;
  &copy;<date-in-citation content-type="copyright-year"
  iso-8601-date="1990">1990</date-in-citation>.
  p. <fpage>214</fpage>-<lpage>216</lpage>.</mixed-citation>
In summary, the title elements allowed in current citations are:
<article-title>
For journal articles
<chapter-title>
For books (deprecated in favor of <part-title>)
<data-title>
For all levels of data sources, or for all levels that are part of the <source>. (data citations only)
<issue-title>
Theme or special title for a journal issue
<part-title>
For the title of a portion, part, or item in a larger resource, a title at a lower hierarchical level than the whole
<trans-title> (deprecated)
This element should not be used. To capture a second title or a translated title, repeat the appropriate title element, with different a @xml:lang attribute and use the multi-language attribute @lang-variant to flag a translation, if appropriate.