gentoo-overlay/app-misc/emelfm2/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<!-- maintainer-needed -->
	<use>
		<flag name="ansi">Add support for ANSI escape sequences</flag>
		<flag name="gtk3">Use <pkg>x11-libs/gtk+</pkg>:3 instead of <pkg>x11-libs/gtk+</pkg>:2</flag>
	</use>
</pkgmetadata>