Container element for one or more contributors and information about those contributors.
The following, in order:
<contrib> Contributor, one or more
Any combination of:
<address> Address/Contact Information
<aff> Affiliation
<aff-alternatives> Affiliation Alternatives
<author-comment> Author Comment
<bio> Biography
<email> Email Address
<ext-link> External Link
<on-behalf-of> On Behalf of
<role> Role or Function Title of Contributor
<uri> Uniform Resource Indicator (URI)
<xref> X (cross) Reference