I host some services at home, mainly targeted at friends and family.

Some are IPv6-only, because it's much easier to manage from my side. I whish I could add an A record for these that pointed to a reserved IP address that would inform clients the service is IPv6-only.

For now, I just don't put any, and browsers just display a generic error. Since some DNS don't answer with IPv6 addresses, the browser couldn't even provide a meaningful error message if it tried to.

Would that be worth an RFC? What IP address should be used?