fonts/etc_fonts/conf.d/69-unifont.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
	<alias>
		<family>serif</family>
		<prefer>
			<family>FreeSerif</family>
			<family>Code2000</family>
			<family>Code2001</family> <!-- plane1 and beyond -->
		</prefer>
	</alias>
	<alias>
		<family>sans-serif</family>
		<prefer>
			<family>FreeSans</family>
			<family>Arial Unicode MS</family>
			<family>Arial Unicode</family>
			<family>Code2000</family> <!-- almost everything; serif actually -->
			<family>Code2001</family> <!-- plane1 and beyond -->
		</prefer>
	</alias>
	<alias>
		<family>monospace</family>
		<prefer>
			<family>FreeMono</family>
		</prefer>
	</alias>
</fontconfig>