media-sound/potamus/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<herd>sound</herd>
<use>
	<flag name="opus">Adds support for the Opus codec.</flag>
</use>
</pkgmetadata>