gentoo-overlay/gnome-base/gnome-settings-daemon/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<maintainer type="project">
		<email>gnome@gentoo.org</email>
		<name>Gentoo GNOME Desktop</name>
	</maintainer>
	<use>
		<flag name="colord">Support color management using
			<pkg>x11-misc/colord</pkg></flag>
		<flag name="openrc-force">Skip systemd dependency (#480336),
			enabling this flag will become your setup to be fully
			unsupported by upstream and downstream Gnome team. Do not
			try to enable it unless completely needed</flag>
	</use>
</pkgmetadata>