gentoo-overlay/app-emulation/virtualbox-bin/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer>
    <email>patrick@gentoo.org</email>
    <name>Patrick Lauer</name>
  </maintainer>
<use>
	<flag name='additions'>Install Guest System Tools ISO</flag>
	<flag name='chm'>Install kchmviewer binary to enable online help (in MS CHM format)</flag>
	<flag name='headless'>Install without any graphic frontend</flag>
	<flag name='sdk'>Enable building of SDK</flag>
	<flag name='vboxwebsrv'>Install the VirtualBox webservice</flag>
	<flag name='rdesktop-vrdp'>Install the rdesktop client integration</flag>
</use>
</pkgmetadata>