montzstar on Nostr: #[0] Is there a way to select only specific relays when you’re posting? The ...

jb55 (npub1xts…kk5s) Is there a way to select only specific relays when you’re posting? The use-case I’m thinking of would be: I could host a relay and only allow my family members to post to it. But I wouldn’t want to send the same posts to public relays. Is that already possible?