Now, I don't know all that much about how the earlier Roblox chat works, but I do know is that all text has to be routed from the client first, then through diogenes.fnt to see if anything needs to be censored, then sent to the server where its then seen by the other clients. My best guess on how to do this would be either a server side script for a traditional chat message, which would break compatibility with Play Solo. Alternatively, you could just use a GUI Message (I don't remember the name of the original object in the 2008 client) that could maybe be relayed to the other players if you want if you wanted to keep compatibility with Play Solo, but this would break compatibility with later versions, and would require some extra work to keep compatibility with later clients. So based on this, it's basically your call on whether or not keeping compatibility with later clients or Play Solo is more important, but unless you really want it to be a standard chat message, I think it'd be easier to make to make a GUI Message (Once again, I don't know what it's called in the 2008 client) and just send it to the other players in a server if you need it.