gentoo-overlay/app-emulation/lxc/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>virtualization</herd>
  <maintainer>
    <email>flameeyes@gentoo.org</email>
  </maintainer>
  <maintainer>
    <email>dev-zero@gentoo.org</email>
  </maintainer>
  <use>
    <flag name="vanilla">
      Avoid adding Gentoo Linux-specific modifications, which include
      the custom init script. This is present as a flag to avoid
      forcing dependencies over users that might not want have them
      around as they use LXC in contexts where the init script is not
      useful.
    </flag>
  </use>
</pkgmetadata>