Container element for one set of keywords (<kwd>s) used to describe a document
A document may have multiple sets of keywords, each with a source that is named by the kwd-group-type attribute.
<!ELEMENT kwd-group %kwd-group-model; >
The following, in order:
<article>
<front>
...
<abstract>...
</abstract>
<kwd-group>
<kwd>DNA analysis</kwd>
<kwd>gene expression</kwd>
<kwd>parallel cloning</kwd>
<kwd>fluid microarray</kwd>
</kwd-group>
</article-meta>
</front>
...
articlemeta.ent