gentoo-overlay/app-arch/p7zip/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer>
    <email>jlec@gentoo.org</email>
    <description>maintainer</description>
  </maintainer>
  <use>
    <flag name="rar">Enable support for non-free rar decoder</flag>
  </use>
</pkgmetadata>