gentoo-overlay/app-misc/mosquitto/metadata.xml

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<!-- maintainer-needed -->
	<use>
		<flag name="bridge">Enable bridge support in the MQTT broker.</flag>
		<flag name="persistence">Store messages and subscriptions to a file.</flag>
		<flag name="srv">Include SRV lookup support.</flag>
		<flag name="websockets">Support the WebSocket protocol.</flag>
	</use>
</pkgmetadata>