PubMed Central XML Tagging Guidelines

Last updated: 4-8-2008
Link to update comments

Please address all tagging questions to pmc@ncbi.nlm.nih.gov .
This page provides detailed instructions for tagging journal articles in XML for submission to PubMed Central beyond simply validating against the NLM DTD.
The PMC Style Checker provides a detailed report of all items in an XML file that do not comply with PMC style. The report will list items as either warnings or errors. The Style Checker is also available for download as a set of XSL stylsheets. The downloadable version has the same functionality as the Online version but it can be run locally. Please consult the Journal Publishing 2.3 tag library for any item that is not detailed here.
To receive style checker and tagging guidelines update announcements, you may subscribe to the PMC-Tagging-Guidelines email list.
DTD
The XML should conform to the NLM Journal Publishing DTD, version 2.3. (http://dtd.nlm.nih.gov/publishing/2.3/index.html)
The DTD is available on the Web: http://dtd.nlm.nih.gov/publishing/2.3/journalpublishing.dtd
The complete Tag Library is available on the web: http://dtd.nlm.nih.gov/publishing/tag-library/2.3/index.html
All of the files are available by FTP ftp://ftp.ncbi.nih.gov/pub/archive_dtd/publishing.
Capitalization
Title Case capitalization is the preferred style for PMC. This primarily applies to <article-title> and <subject>.
Continuous Makeup Articles
When more than one article starts on the same page, treat each as an individual article. Each should be in its own file with a unique filename. Articles that start on the same page will have the same <fpage>. Use the @seq to assign sequence letters so that each article will have a unique fpage/sequence.
Embargo Delay
Generally speaking, all articles for a journal in PMC have the same delay time between the publication date and the time they are available in PMC. In some cases, however, these delays need to be set at the article level rather than at the journal level. See "Release Delay" under Processing Instructions for details on how to tag embargo delays for individual articles.
Empty Elements
Do not use empty elements for the purpose of formatting.
All required elements should have content.
Formatted Text
As a rule, use formatted text (<bold>, <italic>, <sc>, etc) only to set off a piece of information. Do not set entire elements in formatted text. For example, if a <title> is set completely in boldface, do not tag the <bold>. However, if a title has a word or some words set in boldface for emphasis, tag those words using <bold>. Mainly this will apply to <title>, <p> in <abstract>, and <label>. It might also show up in <aff> and "special" sections, like <ack>.
Lanugages
Based on the agreement between the publisher and NLM, PubMed Central may accept non-English articles and/or English articles with non-English parts (titles, abstracts, etc.)
Non-English content needs to be identified with @xml:lang. Unlike nearly all other attributes in XML, the value of language is inherited. This means that all elements inside the one with the language attribute (its descendants) are assumed to be in the same language, unless they explicitly set their own @xml:lang attribute.
In general, the rule for tagging language is that the main lanugage of the article should be set in the @xml:lang on <article>. Any item within the article that is in a different language should be tagged with an @xml:lang to identify the language of that piece.
Note: English is the default value for @xml:lang on <article>, <response>, and <sub-article> and does not need to be set explictly at these levels.
See <abstract> for tagging details.
Links
All links within the document (e.g. tables, figures, display formula) should be tagged with the <xref> element with the appropriate @link-type. See <xref>.
All external links should be tagged with <ext-link> with the appropriate @ext-link-type. See <ext-link>.
All links to related articles (e.g. from a correction to the corrected article) should be tagged with <related-article> with the appropriate @ext-link-type, @related-article-type, and citation information. See <related-article>.
Math
Tag all display formula with MathML mixed markup. Tag inline formula with MathML mixed markup when it cannot be represented by regular article elements and Unicode characters. MathML 2.0 is included in the DTD. Each <mml:math> should have an id.
Do not set math as <tex-math>.
Use <mml:math> to tag mathematical expressions only. Do not use it to tag single characters!
Punctuation
Trailing and extraneous punctuation should not be included for the purpose of formatting.
See <ref-list> examples in the Fully-tagged Samples.
Series Articles
Sometimes articles are part of a series. This series may either be a group of articles all in one issue or a series of articles (like a re-occuring column) spanning issues. Use the <series-title> to identify the title of the series that an article belongs to if appropriate.
Special Characters
Tag special characters with the Unicode hex number in character entity style (&#x263B;, ☻). For accented characters that cannot be represented by a single Unicode value, use the base character and Combining Diacritical Marks (x0300 to x036F) or Combining Diacritical Marks for Symbols (x20D0 to x20E3).
Do not use values from the Private Use Areas: xE000–xF8FF, xF0000–xFFFFD, and x100000–x10FFFD.
Do not use Unicode values designated as control codes. These ranges include but are not limited to x0000–0020, x0080–x009F.
Subjects
PMC uses subjects (under <article-categories>) to sort the issue contents and build the Table of Contents. Subjects can be hierarchical. They may describe the content of the article: Physical Sciences. Or they may give an indication of the type of article: Erratum.
Fully-tagged Samples
Fully-tagged articles in compressed format are available for download here. These files are also viewable as text-only files through these links:
These articles have been adapted from the version in the PMC archive for tagging illustrations only. The full citation of the original article is included at the top of each article.

Index of Document Objects Index of Elements

Document Objects
DOCTYPE declaration
The root element is <article>.
Set the PUBLIC identifier to "-//NLM//DTD Journal Publishing DTD v2.3 200700202//EN".
Set the SYSTEM identifier to "journalpublishing.dtd".
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v2.3 20070202//EN" "journalpublishing.dtd">
Journal Information
Complete journal information should be included in <journal-meta> in each article. See <journal-meta> for the necessary elements.
Article Categories or Subjects
Every article should have <article-categories> with a <subj-group> @subj-group-type="heading". PMC will use the contents of this <subj-group> to build the Table of Contents for the issue.
See related elements: <article-categories>, <subject>.
Article Types
The @article-type is required on <article>. See <article> for details on tagging the attribute. Following is a listing of article types and things to keep in mind while tagging these types of articles.
Book Reviews
can be tagged in a variety of ways. Some general rules for book reviews are:
  • Use @article-type="book-review" in <article>.
  • In all cases, as much information about the book being reviewed should be tagged within <product> in <article-meta>. It is preferred that the order of citation information tagged within <product> follow the NLM Citation Style.
  • The author of the book review (the reviewer) should be tagged as the author of the article. The book authors will be included only in the <product> element.
If the title of the book being reviewed is used as the title of the article, tag the <article> and <article-title> as follows:

Plunkett's Health Care Industry Almanac. Edited by Jack W. Plunkett
and Michelle LeGate Plunkett. Dallas, TX: Corporate Jobs Outlook, 1995.
700p. $125.00. ISBN: 0-9638268-1-6.

The health care system in the 1990s introduced many new terms, such as
"managed health care," "point-of-serive" (POS) plan, and ...


    <article article-type="book-review">
    <title-group>
         <article-title>Plunkett's Health Care Industry Almanac.</article-title>
    </title-group>
The book (product) information should be tagged in <product>.

    <product product-type="book">
      <person-group person-group-type="editor">
        <name>
          <surname>Plunkett</surname>
          <given-names>Jack W.</given-names></name>
        <name>
          <surname>Plunkett</surname>
          <given-names>Michelle LeGate</given-names></name>
      </person-group>
      <source>Plunkett's Health Care Industry Almanac.</source>
      <year>1995</year>
      <publisher-name>Corporate Jobs Outlook</publisher-name>
      <publisher-loc>Dallas, TX</publisher-loc>
      <page-count count="700"/>
      <comment>$125.00</comment>
      <isbn>0-9638268-1-6</isbn>
    </product>
Sometimes a book review has a title of "Book Review" followed by the name of the book reviewed. In this case, tag the title of the book reviewed as a <subtitle>.

Book Review: Mendel's legacy: the origin of classical genetics 


    <article article-type="book-review">
    <title-group>
      <article-title>Book Review</article-title>
      <subtitle>Mendel's legacy:  the origin of classical genetics</subtitle>
    </title-group>
The book (product) information should be tagged in <product>.

    <product product-type="book">
      <person-group person-group-type="author">
        <name><surname>Carlson</surname>
        <given-names>Elof Axel</given-names></name>
      </person-group>
      <source>Mendel's legacy:  the origin of classical genetics.</source>
      <year>2004</year>
      <publisher-name>Cold Spring Harbor Laboratory Press</publisher-name>
      <publisher-loc>Cold Spring Harbor</publisher-loc>
      <page-count count="332"/>
      <isbn>hardback 0-87969-675-3</isbn>
      <comment>US$45.00</comment>
    </product>
Sometimes the title of a book review is neither "Book Review" nor the title of the book being reviewed. Instead it is descriptive of the book or the review. The following example is for a review of JSTOR: A history.

Looking from the Past to the Future 


    <article article-type="book-review">
    <title-group>
      <article-title>Looking from the Past to the Future</article-title>
    </title-group>
The book (product) information should be tagged in <product>.

    <product product-type="book">
      <person-group person-group-type="author">
        <name>
          <surname>Schonfeld</surname>
          <given-names>R C</given-names>
        </name>
      </person-group>
      <source>JSTOR: A history.</source>
      <year>2003</year>
      <publisher-name>Princeton University Press<publisher-name>
      <publisher-loc>Princeton, New Jersey</publisher-loc>
      <page-count count="412"/>
      <isbn>(hardcover) 0-691-11531-1</isbn>
      <comment>US$29.95</comment>
    </product>
Product Reviews
for hardware, software packages, or other media follow the same guidelines provided for Book Reviews, but the example below accounts for some unique features. See Sample 4 for an example.
Use @article-type="product-review" in <article>.

IMMEX Problem Solving Software. Ronald H. Stevens. University of California, Los Angeles, School of Medicine, Department of Microbiology and Immunology, 43-319 CHS, Los Angeles, CA 90024. Demo disk: $30.00. Author/delivery and analysis modules, $450.00. System requirements: IBM-compatible running on a local area network, Microsoft Windows 3.1


    <product product-type="software">
      <person-group person-group-type="inventor">
        <name>
          <surname>Stevens</surname>
          <given-names>Ronald H.</given-names>
        </name>
      </person-group>
      <source>IMMEX Problem Solving Software</source>
      <publisher-name>University of California, Los Angeles, School of Medicine,
                      Department of Microbiology and Immunology<publisher-name>
      <publisher-loc>43-319 CHS, Los Angeles, CA 90024/publisher-loc>
      <comment>Demo disk $30.00.  Author/delivery and analysis modules, $450.00.
               System requirements: IBM-compatible running on a local area network,
               Microsoft Windows 3.1</comment>
    </product>
Corrections/Errata
See Sample 5 for an example.
Retractions
Obituaries
Editorials
See Sample 3 for an example.
In Brief/In This Issue
Letters
Replies
Review Articles
Commentaries
Meeting Reports/Abstracts

The Association of Clinical Pathologists
102nd scientific meeting

The 102nd scientific meeting was held at the Royal Society of Medicine, London 21-22 September 1978. Abstracts of the scientific communications follow.

Infectious mononucleosis with an unusual Paul-Bunnell result

D. Parratt and D. O. Ho-Yen (Departments of Bacteriology and Haematology, Ninewells Hospital and Medical School, Dundee) An 18-year-old girl presented with typical clinical and cytological findings of infectious mononucleosis.

Age-related changes in human thymus

A. K. Singh and Jayanti Singh (St Thomas' Hospital, London) Biopsies of thymus were undertaken in 52 subjects during open-heart surgery. Their ages ranged from 5-75 years.


<article article-type="meeting-report">
  <front>
    <journal-meta>[specific tags omitted]</journal-meta>
    <article-meta>
      <article-categories><subj-group>
        <subject>Meeting Abstracts</subject>
      </subj-group></article-categories>
      <title-group>
        <article-title>The Association of Clinical Pathologists</article-title>
        <subtitle>102nd scientific meeting</subtitle>
      </title-group>
      <pub-date pub-type="ppub"><month>4</month><year>1979</year></pub-date>
      <volume>32</volume>
      <issue>4</issue>
      <fpage>415</fpage>
      <lpage>418</lpage>
    </article-meta>
  </front>
  <body>
    <p>The 102nd scientific meeting was held at the Royal Society of Medicine, London
    21-22 September 1978. Abstracts of the scientific communications follow.</p>
  </body>
  <sub-article article-type="abstract">
    <front-stub>
      <title-group>
        <article-title>Infectious mononucleosis with an unusual Paul-Bunnell
        result</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name><surname>Parratt</surname>
          <given-names>D.</given-names></name>
        </contrib>
        <contrib contrib-type="author">
          <name><surname>Ho-Yen</surname>
          <given-names>D. O.</given-names></name>
        </contrib>
        <aff>Departments of Bacteriology and Haematology, Ninewells Hospital and
        Medical School, Dundee</aff>
      </contrib-group>
    </front-stub>
    <body>[tagged text omitted]</body>
  </sub-article>
  <sub-article article-type="abstract">
    <front-stub>
      <title-group>
        <article-title>Age-related changes in human thymus</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name><surname>Singh</surname>
          <given-names>A. K. </given-names></name>
        </contrib>
        <contrib contrib-type="author">
          <name><surname>Singh</surname>
          <given-names>Jayanti</given-names></name>
        </contrib>
        <aff>St Thomas' Hospital, London</aff>
      </contrib-group>
    </front-stub>
    <body>[tagged text omitted]</body>
  </sub-article>
</article>
Article Title
See related elements: <title-group>, <article-title>, <fn-group>, <subtitle> and <trans-title>
Book review titles can vary; see Book Reviews for tagging examples.
Do not tag emphasis that encompasses the entire title.
Subtitle
Tag only the content of the subtitle in this tag. Do not include formatting that encompasses the entire subtitle.

Treatment of lysosomal storage disorders
Increased awareness and diagnosis are important as treatment is now feasible 


<title-group>
  <article-title>Treatment of lysosomal storage disorders</article-title>
  <subtitle>Increased awareness and diagnosis are important as treatment
   is now feasible</subtitle>
</title-group>
Footnotes on the Title
If there is a footnote to the title, put the <xref> (with @ref-type="fn") in the <article-title> or <subtitle> element, and set the <fn> in the <fn-group> in <back>.

Cathepsin B Regulates the Intrinsic Angiogenic Threshold of Endothelial Cells‡

Eunok Im, Annapurna Venkatakrishnan, and Andrius Kazlauskas
Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114

‡The online version of this article contains supplemental material at MBC Online.


<title-group>
  <article-title>Cathepsin B Regulates the Intrinsic Angiogenic Threshold
                 of Endothelial Cells<xref ref-type="fn" rid="fn1">‡<xref>
  </article-title>
</title-group>

...

<back>
      ...
      <fn-group>
         <fn id="fn1">
             <p><label>‡</label>The online version of this article
                contains supplemental material at MBC Online.</p>
         </fn>
      </fn-group>
Author Names
Each author name and its associated information should be tagged in a <contrib>.
Set the following attributes on <contrib> for these situations.
Situation attribute
corresponding author @corresp="yes"
author is deceased @deceased="yes"
author contributed equally @equal-contrib="yes"
If more information than can be represented with a simple yes/no is supplied for one of these situations, we will need to carry this information in <fn> in <author-notes>. If this is the case, the attribute is not needed.
For example, if the author is indicated just as "Corresponding Author", use the @corresp="yes"
Affiliations
Affiliation information should be tagged in a <contrib> or in the <contrib-group>. See <contrib-group> for more details.
Author/Affiliation Relationship
The relationships between <contrib>, and <aff> can be complex, but we should be able to simplify things here:
All author/affiliations should be tagged in the same style within a given article.
A. If there is an address or affiliation supplied for each <contrib>, include the <aff> in the tagging for the <contrib>.

Lorraine Tanabe§

National Center for Biotechnology Information, National Library of Medicine, NIH, 8600 Rockville Pike, Bethesda, MD, USA

Lynne H. Thom

Consolidated Safety Services, 10335 Democracy Lane, Suite 202, Fairfax, VA, USA

§Corresponding author


<contrib-group>
  <contrib contrib-type="author" corresp="yes">
    <name>
      <surname>Tanabe</surname>
      <given-names>Lorraine</given-names>
    </name>
    <aff>National Center for Biotechnology Information, National Library of
	 Medicine, NIH, 8600 Rockville Pike, Bethesda, MD, USA</aff>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Thom</surname>
      <given-names>Lynne H.</given-names>
    </name>
    <aff>Consolidated Safety Services, 10335 Democracy Lane, Suite 202,
	 Fairfax, VA, USA</aff>
  </contrib>
</contrib-group>
B. If there is one affiliation supplied for all of the contributors, include the <aff> in the tagging for the <contrib-group>.

Authors: Gabor T. Marth1, Eva Czabarka, Janos Murvai, & Stephen T. Sherry.

Affiliations: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894

1Present affiliation: Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467. 


<contrib-group>
  <contrib contrib-type="author">
    <name>
      <surname>Marth</surname>
      <given-names>Gabor T.</given-names>
    </name>
    <xref ref-type="author-notes" rid="FN1">1</xref>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Czabarka</surname>
      <given-names>Eva</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Murvai</surname>
      <given-names>Janos</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Sherry</surname>
      <given-names>Stephen T.</given-names>
    </name>
  </contrib>
  <aff>National Center for Biotechnology Information, National Library of
  Medicine, National Institutes of Health, Bethesda, Maryland 20894</aff>
</contrib-group>
C. If there are multiple <contrib-group>, each with a different <aff>, include the corresponding <aff> in the tagging for the <contrib-group>.

Lorraine Tanabe§ and Natalie Xie,

National Center for Biotechnology Information, National Library of Medicine, NIH, 8600 Rockville Pike, Bethesda, MD, USA

Lynne H. Thom and Wayne Matten

Consolidated Safety Services, 10335 Democracy Lane, Suite 202, Fairfax, VA, USA

§Corresponding author


<contrib-group>
  <contrib contrib-type="author" corresp="yes">
    <name>
      <surname>Tanabe</surname>
      <given-names>Lorraine</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Xie</surname>
      <given-names>Natalie</given-names>
    </name>
  </contrib>
  <aff>National Center for Biotechnology Information, National Library of
  Medicine, NIH, 8600 Rockville Pike, Bethesda, MD, USA</aff>
</contrib-group>
<contrib-group>
  <contrib contrib-type="author">
    <name>
      <surname>Thom</surname>
      <given-names>Lynne H.</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Matten</surname>
      <given-names>Wayne</given-names>
    </name>
  </contrib>
  <aff>Consolidated Safety Services, 10335 Democracy Lane, Suite 202,
  Fairfax, VA, USA</aff>
</contrib-group>
D. If there are complex relationships between authors and contributors, and the relationships are defined by symbols (including letters/numbers) - as below, set the <xref> element with @ref-type="aff" to refer to the corresponding @id on <aff>. The <xref> should be contained within the <contrib>. If there are multiple <xref> elements in the same <contrib>, do not include punctuation between them.
All of the affiliations should follow the single <contrib-group> in this case.

Olga V. Moroz1, Maria Harkiolaki1,2, Michael Y. Galperin3, Alexei A. Vagin1, Dolores González-Pacanowska4 and Keith S. Wilson1

1Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK;

2Cancer Research UK Cell Signalling Group and Weatherall Institute of Molecular Medicine, Oxford, OX3 9DS, UK;

3National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA;

4Instituto de Parasitología y Biomedicina "López-Neyra", C/Ventanilla, 11. 18001 Granada, Spain 



<contrib-group>
  <contrib contrib-type="author">
    <name>
      <surname>Moroz</surname>
      <given-names>Olga V.</given-names>
    </name>
    <xref ref-type="aff" rid="A1">1</xref>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Harkiolaki</surname>
      <given-names>Maria</given-names>
    </name>
    <xref ref-type="aff" rid="A1">1</xref>
    <xref ref-type="aff" rid="A2">2</xref>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Galperin</surname>
      <given-names>Michael</given-names>
    </name>
    <xref ref-type="aff" rid="A3">3</xref>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Vagin</surname>
      <given-names>Alexei A.</given-names>
    </name>
    <xref ref-type="aff" rid="A1">1</xref>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Gonz&#x00E1;lez-Pacanowska</surname>
      <given-names>Delores</given-names>
    </name>
    <xref ref-type="aff" rid="A4">4</xref>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Wilson</surname>
      <given-names>Keith S.</given-names>
    </name>
    <xref ref-type="aff" rid="A1">1</xref>
    <xref ref-type="author-notes" rid="FN1">*</xref>
  </contrib>
</contrib-group>
<aff id="A1">
  <label>1</label>Structural Biology Laboratory, Department of Chemistry,
  University of York, Heslington, York YO10 5YW, UK;
</aff>
<aff id="A2">
  <label>2</label>Cancer Research UK Cell Signalling Group and Weatherall
  Institute of Molecular Medicine, Oxford, OX3 9DS, UK;
</aff>
<aff id="A3">
  <label>3</label>National Center for Biotechnology Information, National
  Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894,
  USA;
</aff>
<aff id="A4">
  <label>4</label>Instituto de Parasitolog&#x00ED;a y Biomedicina
  "L&#x00F3;pez-Neyra", C/Ventanilla, 11. 18001 Granada, Spain
</aff>
E. If the affiliation information has been presented as a single block of text where the relationships between author and affiliation are complex and cannot be separated easily, tag the entire affiliaiton block in one <aff>. Most of the time, the authors' names or initials will be sprinkled through this block of text. This is OK. Also, this block of text might contain other information not exactly related to affiliations. This is OK as well.
Set all of the authors in one <contrib-group> and set the <aff> in this <contrib-group>.

Heloisa P. Soares
Ambuj Kumar
Stephanie Daniels
Suzanne Swann
Alan Cantor
Iztok Hozo
Mike Clark
Fadila Serdarevic
Clement Gwede
Andy Trotti
Benjamin Djulbegovic

Author Affiliations: H. Lee Moffitt Cancer Center & Research Institute at University of South Florida, Tampa (Drs Soares, Kumar, Cantor, Serdarevic, Gwede, Trotti, and Djulbegovic and Ms Daniels); Department of Statistics, Radiation Therapy Oncology Group, Philadelphia, Pa (Dr Swann); Department of Mathematics, University of Indiana Northwest, Gary (Dr Hozo); UK Cochrane Centre, Oxford, England (Dr Clark).


<contrib-group>
  <contrib contrib-type="author">
    <name>
      <surname>Soares</surname>
      <given-names>Heloisa P.</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Kumar</surname>
      <given-names>Ambuj</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Daniels</surname>
      <given-names>Stephanie</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Swann</surname>
      <given-names>Suzanne</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Cantor</surname>
      <given-names>Alan</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Hozo</surname>
      <given-names>Iztok</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Clark</surname>
      <given-names>Mike</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Serdarevic</surname>
      <given-names>Fadila</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Gwede</surname>
      <given-names>Clement</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Trotti</surname>
      <given-names>Andy</given-names>
    </name>
  </contrib>
  <contrib contrib-type="author">
    <name>
      <surname>Djulbegovic</surname>
      <given-names>Benjamin</given-names>
    </name>
  </contrib>
  <aff>Author Affiliations: H. Lee Moffitt Cancer Center & Research Institute at 
  University of South Florida, Tampa (Drs Soares, Kumar, Cantor, Serdarevic, Gwede, 
  Trotti, and Djulbegovic and Ms Daniels); Department of Statistics, Radiation Therapy 
  Oncology Group, Philadelphia, Pa (Dr Swann); Department of Mathematics, University 
  of Indiana Northwest, Gary (Dr Hozo); UK Cochrane Centre, Oxford, England 
  (Dr Clark).</aff>
</contrib-group>

James B. Leverenz, MD
Mark A. Fishel, MD
Elaine R. Peskind, MD
Thomas J. Montine, MD, PhD
David Nochlin, MD
Ellen Steinbart, RN, MA
Murray A. Raskin, MD
Gerard D. Schellenberg, PhD
Thomas D. Bird, MD
Debby Tsuang, MD, MS

Author Affiliations: Parkinson's Disease (Dr Leverenz), Mental Illness (Drs Leverenz, Peskind, Raskind, Schellenberg, and Tsuang and Ms Steinbart), Research, Education, and Clinical Centers, Veterans Affairs Puget Sound Health Care System, Seattle, Wash; and Departments of Neurology (Drs Leverenz, Fishel, and Bird) and Psychiatry and Behavioral Science (Drs Leverenz, Peskind, Raskind, and Tsuang), Division of Neuropathology, Department of Pathology (Drs Montine and Nochlin), and Division of Gerontology/Geriatrics, Department of Medicine (Dr Schellenberg), University of Washington School of Medicine, Seattle.


<contrib-group>
  <contrib>
    <name>
      <surname>Leverenz</surname>
      <given-names>James B.</given-names>
    </name>
      <degrees>MD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Fishel</surname>
      <given-names>Mark A.</given-names>
    </name>
      <degrees>MD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Peskind</surname>
      <given-names>Elaine R.</given-names>
    </name>
      <degrees>MD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Montine</surname>
      <given-names>Thomas J.</given-names>
    </name>
      <degrees>MD</surname>
    </name>
      <degrees>PhD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Nochlin</surname>
      <given-names>David</given-names>
    </name>
      <degrees>MD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Steinbart</surname>
      <given-names>Ellen</given-names>
    </name>
      <degrees>RN, MA</surname>
  </contrib>
  <contrib>
    <name>
      <surname>Raskin</surname>
      <given-names>Murray A.</given-names>
    </name>
      <degrees>MD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Schellenberg</surname>
      <given-names>Gerard D.</given-names>
    </name>
      <degrees>PhD</degrees>
  </contrib>
  <contrib>
    <name>
      <surname>Bird</surname>
      <given-names>Thomas D.</given-names>
    </name>
      <degrees>MD</degrees>
  </contrib>
  <contrib>
    <name>
      <given-names>Debby Tsuang</surname>
    </name>
      <degrees>MD, MS</degrees>
  </contrib>
  <aff>Author Affiliations: Parkinson's Disease (Dr Leverenz), Mental Illness 
  (Drs Leverenz, Peskind, Raskind, Schellenberg, and Tsuang and Ms Steinbart), 
  Research, Education, and Clinical Centers, Veterans Affairs Puget Sound Health 
  Care System, Seattle, Wash; and Departments of Neurology (Drs Leverenz, 
  Fishel, and Bird) and Psychiatry and Behavioral Science (Drs Leverenz, 
  Peskind, Raskind, and Tsuang), Division of Neuropathology, Department of 
  Pathology (Drs Montine and Nochlin), and Division of Gerontology/Geriatrics, 
  Department of Medicine  (Dr Schellenberg), University of Washington School 
  of Medicine, Seattle.</aff>
</contrib-group>
Author Notes
This includes all information related to authors that cannot be expressed with the attributes (@ca, @ce, etc) that can be hung on an author.
See related elements <author-notes>.
Dates
There are two date elements, <date> and <pub-date>. The date model is the same for both. It allows parsed date information (<day>, <month>, <season>, <year>).
The content of <day>, <month>,and <year> should all be integers.
<season> is text.
Month ranges (April-June) should be set in <season>. Do not set the year in <season>. Month ranges should use 3-letter abbreviations separated by an en-dash (U2013).

Received: January 14, 2005


<date date-type="received">
  <day>14</day>
  <month>1</month>
  <year>2005</year>
</date>

Spring-Summer 1999


<pub-date pub-type="ppub">
  <season>Spring-Summer</season>
  <year>1999</year>
</pub-date>

October, 1999


<pub-date pub-type="collection">
  <month>10</month>
  <year>1999</year>
</pub-date>

Apr–Jun 2000


<pub-date pub-type="ppub">
   <season>Apr&#x2013;Jun</season>
   <year>2000</year>
</pub-date>
Copyright Information
Copyright information should be contained within <permissions>.
Set any copyright information that is included in the source material into a <copyright-statement> and <copyright-year> tags. This information may be in a page header or footer or immediately following the abstract.
Copyright Information usually consists of the word "Copyright", a copyright symbol, the copyright year, and the name of the copyright holder. It might also contain notes, such as Disclaimers.
Include the complete copyright statement (with the date and symbol), in <copyright-statement>. The year of copyright should also be tagged in <copyright-year>, whether or not it appears as part of the <copyright-statement>.
Also include any statement about permissions in the <copyright-statement>

Copyright © 2005, Medical Publishing Corp.


<permissions>
    <copyright-statement>Copyright &#169; 2005, Medical Publishing
        Corp.</copyright-statement>
    <copyright-year>2005</copyright-year>
</permissions>

Copyright © Medical Publishing Corp.


<permissions>
    <copyright-statement>Copyright &#169; Medical Publishing
        Corp.</copyright-statement>
    <copyright-year>2005</copyright-year>
</permissions>
Disclaimers
Tag as <notes> in front matter with @notes-type="disclaimer".

The contents of articles or advertising in the journal are not to be construed as official statements or endorsements by the Medical Publishing Corp.


<notes notes-type="disclaimer"><p>The contents of articles or advertising in the
journal are not to be construed as official statements or endorsements by the
Medical Publishing Corp.</p></notes>
Licensing Information
Licensing information should not be confused with Copyright Information. Copyright Information covers who owns the content, and Licensing Information covers how it may be used. The example from the tag library is good. It has three parts: 1. a description or name of the license type in @license-type="open-access", 2. A specific reference to a published definition of the details of the license with @xlink:href="http://creativecommons.org/licenses/by/2.0/", and 3. a text description of the license in the content of <license>.
Licensing information should be captured in <permissions>.

<permissions>
  <copyright-statement>Copyright &#169; 2005 Medical
    Publishing Corp.</copyright-statement>
  <copyright-year>2005</copyright-year>
  <license license-type="open-access"
         xlink:href="http://creativecommons.org/licenses/by/2.0/">
    <p>This is an open-access article distributed under the terms of the
       Creative Commons Attribution License, which permits unrestricted use,
       distribution, and reproduction in any medium, provided the original
       work is properly cited.</p>
  </license>
</permissions>
Grant and Contract Information
Grant and contract information should be tagged in <contract-num> and <contract-sponsor> to build article metadata. Any prose that describes this information (e.g., "Part of the research at Stanford was supported by NIH GM61374.") should be tagged in an article-level footnote.
Body
The article body should be pretty straightforward. There are only a few points.
Sections/Subsections
Sections and subsections are identifiable by their titles or labels. If an article does not have a labeled or titled opening section, do not tag one in the XML. Where possible, identify @sec-type.

Introduction

Planning in advance is widely encouraged as a way to improve quality of care at the end of life.1 Cross cultural studies have shown that healthcare providers and patients often differ in their views on health related matters....

Methods

We carried out a focused ethnographic study8 within a care programme for elderly people in east Baltimore, United States. For the past 20 years this programme has provided medical and nursing care to generally frail housebound elderly people (mean age 77 years) in a largely working class community.


<body>
<sec sec-type="intro">
<title>Introduction</title>
<p>Planning in advance is widely encouraged as a way to improve quality
of care at the end of life.<xref ref-type="bibr" id="R1">1</xref>
Cross cultural studies have shown that healthcare providers and patients
often differ in their views on health related matters....</p>
</sec>
<sec sec-type="methods">
<title>Methods</title>
<p>We carried out a focused ethnographic study
<xref ref-type="bibr" id="R1">8</xref> within a care programme
for elderly people in east Baltimore, United States. For the past 20
years this programme has provided medical and nursing care to
generally frail housebound elderly people (mean age 77 years) in a
largely working class community.</p>

It has now been 50 years since Briggs and King...published their paper showing that normal hatched tadpoles can be obtained by transplanting the nucleus of a blastula cell to the enucleated eggs of Rana pipiens. This finding provided an initial answer to the long-standing question of whether the process of development and cell differentiation requires a loss or stable change in the genetic constitution of cells....

Amphibia

Briggs and King's immediate pursuit of their 1952 breakthrough gave the somewhat surprising result that, whereas blastula nuclei supported normal tadpole development in up to 40% of all tests, gastrula nuclei were markedly less successful. By the tail-bud stage, nuclei of the endoderm (and in later work nuclei of other germ layers) gave only abnormal embryo development ..., even though the nuclei of tail-bud germ cells gave a high proportion of tadpole development....


<body>
<p>It has now been 50 years since Briggs and King...published their paper
showing that normal hatched tadpoles can be obtained by transplanting the
nucleus of a blastula cell to the enucleated eggs of Rana pipiens. This
finding provided an initial answer to the long-standing question of whether
the process of development and cell differentiation requires a loss or
stable change in the genetic constitution of cells....</p>
<sec>
<title>Amphibia</title>
<p>Briggs and King's immediate pursuit of their 1952 breakthrough gave
the somewhat surprising result that, whereas blastula nuclei supported
normal tadpole development in up to 40% of all tests, gastrula nuclei were
markedly less successful. By the tail-bud stage, nuclei of the endoderm
(and in later work nuclei of other germ layers) gave only abnormal embryo
development ..., even though the nuclei of tail-bud germ cells gave a high
proportion of tadpole development....</p>
Lists
Use the <list> only to represent content in lists. Do not use it for formatting.
There are labeled and unlabeled lists. These styles are controlled by the @list-type. The labels will be applied based on the @list-type. Do not set the labels in the <list-item>. The only exception to this is when a list must start with a particular value. In this case, set the <label> on each <list-item>.
A <list> may be included in the contents of a <list-item> to build a multi-level list or outline.
See <list>.
Boxed Text
Any object (<fig>, <table>, <media>) contained within boxed text must have the specified value @position="anchor".
Footnotes
Capture footnotes in relative proximity to the part of the article in which it is referenced. For instance, capture author footnotes in <author-notes> and footnotes that apply to the article as a whole in a <fn-group> in the article <back>.
See <fn-group>, <author-notes>, <fn>.
See Sample 2 for examples.
Signatures
Signature blocks should be captured in <sig-block> with each signature tagged in its own <sig>.
See Sample 3 for an example.

Denton A. Cooley, MD, Surgeon-in-Chief,
Texas Heart Institute at
St. Luke's Episcopal Hospital,
Houston
 


  <sig-block>
  <sig>Denton A. Cooley, MD<break/>
    President, Texas Heart Institute at St. Luke's 
    Episcopal Hospital, Houston</sig>
  </sig-block>
Methods Section
All Methods sections in the <body> (with titles like "Methods", "Materials and Methods", "Experimental Procedures", "Procedures") should have @sec-type="methods".
Do not use @sec-type for sections inside <abstract>.
Labels
<label> can appear in most any object. Set the label whenever possible except in <list-item>.
Do not format the content in a label; all formatting will be supplied on the rendering side. Do no include <sup>, <bold>, or <italic> (either inside <label><sup>4<sup><label> or outside <sup><label>4<label><sup>) in an attempt to match the style of the label in the manuscript.
Related Articles
Articles directly related to the current content should be tagged as <related-article>. These typically appear in corrections and commentaries.
External Links
All external links should be tagged with <ext-link>.
URLs
Any Web link should be tagged with @ext-link-type="uri". The value of the @xlink:href should include the complete web address. The contents of the <ext-link> can be a repeat of the web address or any content that will be "hot".
GenBank
GenBank numbers should be tagged with @ext-link-type="entrez-genbank".
Figures & Tables
Referenced figures and tables should be tagged at their first callout in the text. Unreferenced figures and tables should be tagged in <floats-wrap> at the end of the <article>. See Figures and Tables for more details.
Figures
Figures are the article-level objects that (usually) contain a <graphic>. We need to distinguish between an object that is a figure and an image that needs to be displayed in place in the text.
Set as a <fig> with @position="float" any "figure" or image that
  • is named - like "Fig. 1" or "Schema IV" or even just "Figure". This name should be included in the <label>.
  • has a Title or Caption
  • is reference by an <xref> @ref-type="fig".
Set as <graphic> in a <p> or <sec> any image that must remain at the paragraph level.
Set as <inline-graphic> in a <p> any image that needs to be displayed in the flow of the text.
There is a rare occasion when a named figure (usually it is called something different, like "Scheme") needs to stay anchored in it's position in the text. There may be a <label> and <caption>. In these instances, use @position="anchor" on <fig>. Figures that appear inside appendices (<app>) should also be tagged with @position="anchor".
Figure Groups
Figures should not be tagged together into <fig-group>. Each should have its own caption and <graphic> (if appropriate).
If you come across content that you think needs to be tagged as a <fig-group>, contact PMC.
See Sample 2 for examples.
Tables
Tables are the article-level objects that contain tabular material - usually in a <table-wrap>. We need to distinguish between an object that is a table and a content that must be displayed in tabular form in the flow of the text.
Set as a <table-wrap> with @position="float" any "table" that
  • is named - like "Table II" or even just "Table". This name should be included in the <label>.
  • has a Title or Caption
  • is reference by an <xref> @ref-type="table".
There are occasions when a named table needs to stay anchored in it's position in the text. There may be a <label> and <caption>. In these instances, use @position="anchor". Tables that appear inside an appendix (<app>) are examples of tables whose @position="anchor".
Set as <array> in a <p> or <sec> any tablular material that must remain at the paragraph level.
Table Groups
Tables should not be tagged together into <table-wrap-group>.
If you come across content that you think needs to be tagged as a <table-wrap-group>, contact PMC.
See Sample 2 for examples.
Table Coloring and Shading
Coloring and shading within table rows and cells should only be used to convey information. Background and font colors can be set within the elements <td>, <tr> and <th> using @content-type attribute.
  • For text color: <td content-type="color:#990099">1R</td>
  • For background shading: <tr content-type="background-color:#CCCCFF"></tr>
  • For both: <th content-type="background-color:#66FFFF;color:#003300">Cadaver</th>
Use hexadecimal color codes in the attribute.
Questions & Answers
There is not a specific set of elements for tagging Questions & Answers. Use <list> with @list-content="QandA".
Include each question/answer in a <list-item>. Use the @list-type to set the number style, bullets, or simple (unlabeled).

Question: How many feet in a mile?

Answer: 5280


<list list-content="QandA">
  <list-item>
    <p content-type="question">How many feet in a mile?<p>
    <p content-type="answer">5280<p>
  </list-item>
</list>

1. How many feet in a mile?

 5280

2. How many kilometers in a mile?

 1.609344


<list list-content="QandA" list-type="order">
  <list-item>
    <p content-type="question">How many feet in a mile?<p>
    <p content-type="answer">5280<p>
  </list-item>
  <list-item>
    <p content-type="question">How many kilometers in a mile?<p>
    <p content-type="answer">1.609344.<p>
  </list-item>
</list>

1. What is the recommended daily dosage?

 a. 2 mg     b. 12 mg
 c. 16 mg     d. 5000 mg

 Answer: 12 mg


<list list-type="order" list-content="QandA">
  <list-item>
    <p content-type="question">What is the recommended daily dosage?
	    <list list-type="alpha-lower">
         <list-item>2 mg</list-item>
         <list-item>12 mg</list-item>
         <list-item>16 mg</list-item>
         <list-item>5000 mg</list-item>
	    </list>
	 </p>
    <p content-type="answer">12 mg</p>

</list>
Inline images
Set as <graphic> in a <p> or <sec> any image that must remain at the paragraph level.
Set as <inline-graphic> in a <p> any image that needs to be displayed in the flow of the text.
See Figures for more details.
Inline tabular material
Tag inline tabular material (anchored tables ) with @position="anchor" .
See Tables for more details.
Display formula
Tag all <disp-formula> with MathML.
Although we would prefer to have all of the math tagged as MathML, it is acceptable to include images of formulas.
Use the <disp-formula> element so that the object can still be identified as a display formula (and referenced) in the article. <disp-formula> allows <graphic>, which should be used to call the image.
See Sample 2 for examples.
Alternate formats of the same object
Where multiple formats of an object (such as a graphic file, media object, and chemical structure) are available, this attribute indicates that a format is a secondary one and describes its relationship to the primary format. The value of @alternate-form-of must be the ID of the primary format.
For PMC's purposes, the attribute @alternate-form-of should be used on <array>, <chem-struct>, <graphic>, <media>, <mml:math>, <preformat>, <table>, and <tex-math>. @alternate-form-of should not be necessary on <inline-formula>, <disp-formula>, or <supplementary-material>, since these elements are used to contain the various formats of a given object.

<tex-math> and <graphic> are alternate forms of the primary object <mml:math> in this example.


	<disp-formula id="Eq0001">
		<mml:math id="Eq0001-mml">
			<mml:mi>E</mml:mi>
			<mml:mo>=</mml:mo>
			<mml:mover>
				<mml:mrow>
					<mml:mi>m</mml:mi>
					<mml:mi>c</mml:mi>
				</mml:mrow>
				<mml:mn>2</mml:mn>
			</mml:mover>
		</mml:math>
		<tex-math alternate-form-of="Eq0001-mml">
			\documentclass[10pt]{article}
			\usepackage{wasysym}
			\usepackage[substack]{amsmath}
			\usepackage{amsfonts}
			\usepackage{amssymb}
			\usepackage{amsbsy}
			\usepackage[mathscr]{eucal}
			\usepackage{mathrsfs}
			\usepackage{pmc}
			\usepackage[Euler]{upgreek}
			\pagestyle{empty}
			\oddsidemargin -1.0in
			\begin{document}
			
			\[
			E = mc^{2}
			\]
			
			\end{document}
		</tex-math>
		<graphic alternate-form-of="Eq0001-mml" xlink:href="biotes-01-100-e001.tif"/>
	</disp-formula>
Inline formula
Most <inline-formula> can be tagged with XML elements and Unicode characters.
Only tag inline math in MathML if it cannot be represented with regular elements. For example, any radical or built fraction.
See Sample 2 for examples.
Notes in Proof
Tag as <notes> in back matter with @notes-type="note-in-proof".
Supplementary Material
Supplementary material is treated as an article-level object (like <fig> or <table-wrap>). If it is referenced, it must have an @id. It may have a <label>.
See Sample 2 for examples.
Generated Text
Generated text should not be tagged in the XML. This includes (but is not limited to) punctuation between multiple <xref> elements, numbers or letters in an ordered list that has no anomalies (1a, 1b, 2, etc), and punctuation in fully tagged <nlm-citation> elements.
References
A <ref-list> is a set of <ref>. Generally each <ref> contains a single <citation> or <nlm-citation>. See Sample PubMed Central Citations for fully-tagged examples of citations.
Multiple citations in one ref

6. (a) De Albuquerque IL, Galeffi C, Casinovi CG, Marini-Bettolo GB. Gazz Chim Ital.
1964;94:287. (b) Alcantara, A. F. de C.;Souza, MR.; Pilo-Veloso, D. Fitoterapia. 2000;71:613.


      <ref id="R6">
        <label>6</label>
        <citation citation-type="journal">
          <label>(a)</label>
          <person-group person-group-type="author">
            <name>
              <surname>De Albuquerque</surname>
              <given-names>I. L.</given-names>
            </name>
            <name>
              <surname>Galeffi</surname>
              <given-names>C.</given-names>
            </name>
            <name>
              <surname>Casinovi</surname>
              <given-names>C. G.</given-names>
            </name>
            <name>
              <surname>Marini-Bettolo</surname>
              <given-names>G. B.</given-names>
            </name>
          </person-group>
          <source>Gazz. Chim. Ital.</source>
          <year>1964</year>
          <volume>94</volume>
          <fpage>287</fpage>
        </citation>
        <citation citation-type="journal">
          <label>(b)</label>
          <person-group person-group-type="author">
            <name>
              <surname>Alcantara</surname>
              <given-names>A. F. de C.</given-names>
            </name>
            <name>
              <surname>Souza</surname>
              <given-names>M. R.</given-names>
            </name>
            <name>
              <surname>Pilo-Veloso</surname>
              <given-names>D.</given-names>
            </name>
          </person-group>
          <source>Fitoterapia</source>
          <year>2000</year>
          <volume>71</volume>
          <fpage>613</fpage>
        </citation>
      </ref>
Notes or end notes in a ref

9. The addition of water (100 mol %) afforded the cyclic ether 2 in quantitative yield and with excellent selectivity (entry 4). This further supports the notion that triethylsilyl bromide is not the active catalyst.


<ref id="R9">
   <label>9</label>
   <note>
      <p>The addition of water (100 mol %) afforded the cyclic ether 
      <bold>2</bold> in quantitative yield and with excellent selectivity 
      (entry 4). This further supports the notion that triethylsilyl bromide is 
      not the active catalyst.</p>
      </note>
   </ref>
Note with a citation

8. For an alternative mechanistic proposal that suggests the triethylsilyl bromide formed from triethylsilane and bismuth tribromide behaves as a Lewis acid catalyst, see: Bajwa JS, Jiang X, Slade J, Prasad K, Repic O, Blacklock TJ. Tetrahedron Lett. 2002;43:6709.


      <ref id="R8">
        <label>8</label>
        <note>
          <p>For an alternative mechanistic proposal that suggests the triethylsilyl 
          bromide formed from triethylsilane and bismuth tribromide behaves as a Lewis 
          acid catalyst, see: <citation citation-type="journal">
              <person-group person-group-type="author">
                <name>
                  <surname>Bajwa</surname>
                  <given-names>J. S.</given-names>
                </name>
                <name>
                  <surname>Jiang</surname>
                  <given-names>X.</given-names>
                </name>
                <name>
                  <surname>Slade</surname>
                  <given-names>J.</given-names>
                </name>
                <name>
                  <surname>Prasad</surname>
                  <given-names>K.</given-names>
                </name>
                <name>
                  <surname>Repic</surname>
                  <given-names>O.</given-names>
                </name>
                <name>
                  <surname>Blacklock</surname>
                  <given-names>T. J.</given-names>
                </name>
              </person-group>
              <source>Tetrahedron Lett.</source>
              <year>2002</year>
              <volume>43</volume>
              <fpage>6709</fpage>
            </citation>
          </p>
        </note>
      </ref>
Note with citations and text mixed

17. Chatterjee AK, Morgan JP, Scholl M, Grubbs RH. J Am Chem Soc. 2000;122:3783. For a recent review on olefin cross-metathesis, see: Connon SJ, Blechert S. Angew Chem Int Ed. 2003;42:1900.


      <ref id="R17">
        <label>17</label>
        <note>
          <p>
            <citation citation-type="journal">
              <person-group person-group-type="author">
                <name>
                  <surname>Chatterjee</surname>
                  <given-names>A. K.</given-names>
                </name>
                <name>
                  <surname>Morgan</surname>
                  <given-names>J. P.</given-names>
                </name>
                <name>
                  <surname>Scholl</surname>
                  <given-names>M.</given-names>
                </name>
                <name>
                  <surname>Grubbs</surname>
                  <given-names>R. H.</given-names>
                </name>
              </person-group>
              <source>J. Am. Chem. Soc.</source>
              <year>2000</year>
              <volume>122</volume>
              <fpage>3783</fpage>
            </citation> 
            For a recent review on olefin cross-metathesis, see: 
            <citation citation-type="journal">
              <person-group person-group-type="author">
                <name>
                  <surname>Connon</surname>
                  <given-names>S. J.</given-names>
                </name>
                <name>
                  <surname>Blechert</surname>
                  <given-names>S.</given-names>
                </name>
              </person-group>
              <source>Angew. Chem. Int. Ed.</source>
              <year>2003</year>
              <volume>42</volume>
              <fpage>1900</fpage>
            </citation>
          </p>
        </note>
      </ref>
Response and Sub-Article
A <response> is a direct response or answer to a question or proposed topic presented in the parent <article>. Usually a <response> cannot stand on its own, requiring the parent <article> to provide necessary context for the content.
A <sub-article> is content written on the same topic as the parent <article>, but is not a direct answer to it. Understanding its content is not dependent on the context provided by the parent <article>.
Each <response> and <sub-article> must contain its own front matter. In most cases, the abbreviated model in <front-stub> is sufficient for properly tagging both. Each <response> and <sub-article> inherits any front matter not explicitly tagged in <front-stub> from its parent <article>.
Each <response> must specify the @response-type and each <sub-article> must specify @article-type.
Fully-tagged samples of both <response> and <sub-article> are available in a compressed zip file or individually here:
Processing Instructions
The following Processing Instruction(s) can be used for PubMed Central articles:
Release Delay
Use the PI <?release-delay x|y ?> to set the release delay for an individual article. The article-level delay will override any delay defined in PMC on the journal level.
  • x is the number of months in the delay
  • y is the number of days in the delay
Both a "month" and "day" value should be included in each PI. Use "0" for "0".
  • <?release-delay 6|0 ?> — a delay of 6 months.
  • <?release-delay 0|14 ?> — a delay of 2 weeks.
  • <?release-delay 12|0 ?> — a delay of 1 year.
  • <?release-delay 0|0 ?> — no delay (this is useful for immediate-release articles in a journal that normally has a delay set.
  • <?release-delay 3|15 ?> — a delay of 3 months and 15 days.
Elements
<abbrev-journal-title>
Used to hold a shortened form of the journal title.
<abstract>
There may be more than one abstract in an article. If there is, identify each with an @abstract-type.
<abstract> allows <title>, <p>, and <sec>.
Only set a <title> if a title is something other than "Abstract".
Only use <sec> if the abstract has been divided into sections. Most abstracts can be tagged with just <p>. However, if an abstract is divided into sections, use the <sec>. Do not just set the section titles in <bold> or other formatting.
Do not use @sec-type for sections inside <abstract>.
Do not include Citation Information and/or Copyright Information at the end of the abstract. This information should be included elsewhere in the <article-meta>.
Any keywords should be set in <kwd-group>. Do not include keywords in the <abstract>.
See Sample 1 for examples.
Use @xml:lang for articles with abstracts in multiple languages.
English article with non-English title and/or abstract
An English article does not need to have an @xml:lang at the <article>. A non-English article title should be tagged as a <trans-title> within <title-group>. A non-English abstract should be tagged as a <trans-abstract> following the <abstract>.
Non-English article with English title and/or abstract
Set the @xml:lang value to the main language of the article on the <article>. Use <trans-title> within <title-group> and <trans-abstract> to set the English translation of the article title and abstract (or for any other language version that is not in the main language of the article.
<aff>
Within <aff> it is not necessary to identify and tag each element of the address.
Set any label or symbol in the <label> element.
Do not add symbols or labels to define the relationship between contributors and affiliations.
Put the rest of the affiliation information into the <aff> as PCDATA. Follow copy for all punctuation.
See Author/Affiliation Relationship for information on how authors and affiliations are "linked".
See Sample 1 and Sample 2 for examples.
<article>
The root element. It allows <front>, <body>, <back>, <sub-article>, and <response>.
If namespace declarations for MathML and XLink are needed in the article, tag them as attributes on the article (see below).
attributes:
  • article-type—Most of the articles should have the value of "research-article". Allowed values are: "abstract", "addendum", "announcement", "article-commentary", "book-review", "books-received", "brief-report", "calendar", "case-report", "correction", "discussion", "editorial", "in-brief", "introduction ", "letter", "meeting-report", "news", "obituary", "oration ", "other", "product-review", "reply", "research-article", "retraction", "review-article". See the Tag Library for descriptions of these values. (#REQUIRED)
  • dtd-version—Do not use.
  • xmlns:mml—Fixed value "http://www.w3.org/1998/Math/MathML"
  • xmlns:xlink—Fixed value "http://www.w3.org/1999/xlink"
<article-categories>
This is a required element that holds subject and other "sorting" type information about the article. PMC requires that there be a <subj-group> with @subj-group-type="heading" to hold headings used to sort the articles on the TOC.
The content of the <subject> may describe the type of article ("Editorial", "Obituary") or the content of the article ("Physical Sciences", "Psychology"). If no subject is available, use "Article".
A set of subjects may have multiple levels, see the Tag Library for more details.
Other <subj-group> with different @subj-group-type may be included.
<article-id>
Contains any unique identifier assigned to the article, such as pii, doi, or PubMed ID.
Each <article-id> can store a single identifier.
See Sample 2 for examples.
attributes:
  • pub-id-type—Use values defined in Tag Library.
<article-meta>
Contains information specific to the article, like citation information and the Abstract. It includes the following elements, in order:
<article-id> - contains any unique identifier assigned to the article.
<article-categories> - use tagging supplied under Article Categories or Subjects.
<title-group> - this includes the article title/subtitle
<contrib-group> - contains contributor information. <contrib-group> and <aff> may interleave.
<author-notes> - contains notes with information specific to the author(s).
<pub-date> - holds the publication date of the article.
<license> - contains information about terms of use of the content.
<self-uri> - a link to a different version of the article.
<abstract> - the article's abstract.
<kwd-group> - keywords, if supplied.
<contract-num> - contract number. This should link to/from <contract-sponsor>.
<contract-sponsor> - contract sponsor. This should link to/from <contract-number>.
<counts> - counts of objects in the article.
<custom-meta-wrap> - custom metadata (might not need this one yet).
<article-title>
This contains the article title exactly as it appears on the article.
If the article is a Book Review, use the explicit title found on the article. If no explicit title is present, use the title of the first (or only) book being reviewed. Then, use <product> to include detailed information about the title being reviewed; see Article Title for examples.
<author-notes>
This is a wrapper element for any footnotes that relate directly to the author. It includes <fn> and <corresp>. Correspondence information (beyond a simple corresponding author yes/no; see Author Names) should be set in <corresp>. All other author-related footnotes should be set in <fn>. Appropriate @fn-type values include:
Value Meaning
com article was communicated by
con article was contributed by
current-aff current affiliation
deceased Person has died since the article was written.
equal contributed equally in the creation of the document
present-address contributor's current address
See Sample 1 for an example.
<back>
Carries all of the article backmatter. It allows <ack>, <app-group>, <bio>, <fn-group>, <ref-list>, <glossary>, <notes>, and <sec>.
Do not set <title>.
<fn-group> should be used to hold all article-level footnotes.
<body>
carries all of the article body. It allows <p> and all paragraph-level objects and then repeating recursive sections (<sec>).
Use <title> for section titles. Do not just set the section titles in <bold> or other formatting.
All named Figures and Tables should be collected in a <sec> in <back>.
Back matter elements, such as <app-group>, <glossary> and <ref-list>, should not appear at the end of <body>.
<caption>
Within the caption, a <title> should be tagged separately from other text of the caption (inside <p>). Do not tag the object's identifying number here, instead use <label>.
<citation>
contains a bibliographic description of a work.
<citation> can appear within body or <ref-list>. It should include a citation-type attribute.
See Sample PubMed Central Citations for fully-tagged examples.
attributes:
  • citatio