Actually, I should have said an “authorization”. I typically say “script”, but the real term is an authorization.
There are doctors on your committee, so they can correct me, but a prescription is for when the doctor can refer to certain criteria. For example, if you have pneumonia, you're going to take penicillin—a certain dosage per day times seven days. In the case of marijuana, that does not exist.
The “authorization” they often write on the same pad as you would a prescription, but the doctor says, “I authorize my client to have three grams a day”. It's not a prescription, because in the drug world this is not a classified drug. It doesn't fall under that category; therefore, it's not a prescription.
The piece of paper is usually just about the same. There's no issue there, but it's the terminology.