gentoo-overlay/media-libs/devil/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>games</herd>
  <use>
    <flag name="allegro">Add support for Allegro</flag>
	<flag name="nvtt">Add support for <pkg>dev-util/nvidia-texture-tools</pkg></flag>
  </use>
</pkgmetadata>