Talking in code...

[mole]

I don't think it's that useful. Chances are the mafia is looking harder for hints like that than the town is, so if, say, you're trying to subtly claim cop to get someone lynched, don't try to do it in code. Half the townies won't work it out and some might think you're suspicious.

Or if you're about to be lynched, well, nobody likes to be given cryptic clues then.

IMO you should just state your role, or find a better way to do things that doesn't involve hints.

[mole]

The mason example DP mentioned is the only one I'd consider useful.

Perhaps if you were mafia and you were about to be lynched and you wanted to give a signal to kill the fourth guy on your bandwagon because you think he's the cop... otherwise it can wait until night. Remember that the fewer/better encoded messages you use, the more likely it is that you'll survive to tell everyone what you mean in English.