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

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
    <maintainer type="project">
        <email>mate@gentoo.org</email>
        <name>Gentoo MATE Desktop</name>
    </maintainer>
	<use>
		<flag name="caja">Enable engrampa to integrate with
			<pkg>mate-base/caja</pkg> by providing entries in its context 
			menu</flag>
		<flag name="magic">Enable filetype auto-detection via
			<pkg>sys-apps/file</pkg></flag>
	</use>
    <upstream>
        <remote-id type="github">mate-desktop/engrampa</remote-id>
    </upstream>
</pkgmetadata>