Container element for one or more contributors and information about those contributors.
One or more of any of:
<contrib> Contributor
<address> Address/Contact Information
<aff> Affiliation
<aff-alternatives> Affiliation Alternatives
<author-comment> Author Comment
<bio> Biography
<email> Email Address
<etal> Et Al.
<ext-link> External Link
<fn> Footnote
<on-behalf-of> On Behalf of
<role> Role or Function Title of Contributor
<uri> Uniform Resource Indicator (URI)
<xref> X (cross) Reference
<x> X - Generated Text and Punctuation