gentoo-overlay/media-gfx/postr/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<herd>gnome</herd>
<use>
	<flag name="gnome2">Install plugin for <pkg>=gnome-base/nautilus-2*</pkg>.
		Warning: will make =nautilus-3* crash.</flag>
</use>
</pkgmetadata>