[JAILBREAK] Sign that shows someones typing

[Byte]

This is impossible.
When you start typing, your game client doesn't send any sort of update to the game server until you press enter and the message is sent.
So there is no way to actually know if someone is typing or not.

And there is no point displaying it if someone isn't moving as they may not be typing.
Wardens/people in general should just be a little lenient if they aren't sure if someone is typing.
People typing should type in small sentences instead of one long sentence to avoid being killed etc.

Good suggestion though but not possible.

EDIT: Semi possible if people change their binds to use some custom command when they hit 'y' but wouldn't work for people who don't use the bind so not a good idea.