how can you tell which relays support it?
Discussion
We need better ways to explain what a relays supports but delete is nip-09 and in many nostr apps you can see what specs a relay supports. 
so if I want my posts to be delete-able I need to only post to relays that allow nip-09 and make sure my client supports that too?
We won’t let you post to a relay that doesn’t support delete for expiring messages in nostr:npub1pu3vqm4vzqpxsnhuc684dp2qaq6z69sf65yte4p39spcucv5lzmqswtfch but we don’t have a setting for all posts yet. Nor do we explain that well in the relay section. Things to do.
Oh interesting. I’m on Damus but might give that a try then.
Is there a chart of what nips do what?
Here’s the list. https://github.com/nostr-protocol/nips
Tyvm