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

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<use>
		<flag name="all_sfx">
			Install all SFX (Self-Extracting) files rather than just the native
			format (allows creation of Windows EXEs on Linux ELF systems)
		</flag>
	</use>
</pkgmetadata>