iirc it was briefly banned as a peace offering to blahaj zone but after the debacle with them it was explicitly re allowed so now you just do it like this:

@zerocool @lemm.ee is a racist slavery apologist

Edit: oh shit oops just realised that's someone with the same username and the same instance, very sorry for the ping if you're reading this

The racist person's @ is @DadeMurphy@lemm.ee