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

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<maintainer><email>hanno@gentoo.org</email></maintainer>
	<maintainer>
		<email>slyfox@gentoo.org</email>
		<name>Sergei Trofimovich</name>
	</maintainer>

	<use>
		<flag name='fluidsynth'>use <pkg>media-sound/fluidsynth</pkg> for MIDI emulation</flag>
	</use>
</pkgmetadata>