syntax is described above, in <ref id="pkg-controlfields">.
<list compact="compact">
+ <item><qref id="f-Format"><tt>Format</tt></qref></item>
<item><qref id="f-Source"><tt>Source</tt></qref> (mandatory)</item>
<item><qref id="f-Version"><tt>Version</tt></qref> (mandatory)</item>
<item><qref id="f-Maintainer"><tt>Maintainer</tt></qref> (mandatory)</item>