The element <comm-ref> identifies the Technical Committee, Subcommittee, or Working Group responsible for the standard, for example, ISO/TC 27/SC 4. The element <comm-ref-group> holds multiple standards-producing groups to create a hierarchy of groups, since the element may contain a <comm-ref> element to name itself, a series of lower-level <comm-ref>s, as well as lower-level <comm-ref-group>s. This @comm-ref-group-type attribute names the type of group, for example, partner or sponsor.