Relays that cater to a community (around a common interest, goal or group of people). To do that job well community admins can set whatever limits to reading/writing they like. Tools in their toolbox: - price lists - white lists - guidelines - automation offered by their hosting solution (rate limiting, spam detection, ...)

For this it's important that the relay also let read and write for allowed people only. Which relays software/code can currently do all of that?