A grouping element to hold the names of multiple standards-producing groups (such as Committees and Subcommittees) that are responsible for the standards document (tagged as <comm-ref>s). A hierarchy of groups is possible as this element may contain a <comm-ref> element to name the top-level group as well as lower-level <comm-ref-group> elements to name subgroups.
The following, in order:
<comm-ref> Committee Reference, one or more
<comm-ref-group> Committee Reference Group, zero or more