Tournament backing/trading %s form?

[Jasonfp]

I traded a % with a friend in a big live tournament and he makes the final table. I thought I remembered reading a thread about a form or something that you could fill out so the casino could pay out the percent owed to the other person without having the tax problem for the player who cashes.
I tried searching for a while and couldn't come up with anything. Any help or link to an original thread would really be appreciated.
thanks
-Jason