I know for sure that Fairfax Tournaments are a go for it. I have seen many people do it. But, beforehand call a judge over to clarify with your opponent. Bring looseleaf paper, and fold it so your opponent cant see it. Only thing is the judge has to now what your are writing. So if a Magnezone is prized you cannot just write MGZE as 1). Prize card. You have to draw prize cards on paper, and write out full card names when you write it out. and anyone want to use apprentice? It's pretty cool.