There was a gentleman who got on the train the other day in Melbourne (it was fairly full) and went to the priority seat & asked if he could sit down. He LOOKED physically fine/fit. He asked the gentleman & lady if they had a medical need to sit down b/c he did (it was something where he couldn't stand for long periods of time) and went to present them with a medical certificate or letter. I thought to myself, 'how terrible that he has to provide proof just b/c you can't tell he needs to sit there' but then again after what PZ said about that bargy woman, it's no wonder. (BTW the gentleman told him he didn't need to see the certificate and gave him his seat)