Farcaster Devs

Is there a way for a client to tag a cast with a flag that prevents other clients from indexing the cast?

Eg. say I'm building Hypercast, and I only want Hypercast to show certain casts. Right now, if a user makes a cast, and it gets sent to hubs, all clients will show this cast by default. Is there an alternative?

just force prefix a byte of data on the cast and prune it on your client view until it becomes part of the protocol. 

suggested this idea a long time ago but the geniuses didn’t seem sold on it

Will the hub still store it?

And I guess client validation will reject the message due to the prefix, unless the client is aware?

should do, it’s part of the cast body but it’ll look weird on other clients that doesn’t understand the non standard