gentoo-overlay/kde-base/dolphin/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<use>
	<flag name="thumbnail">
		Enables video thumbnails generation for <pkg>kde-base/dolphin</pkg> file manager.
	</flag>
</use>
<herd>kde</herd>
</pkgmetadata>