I have been asked for my AS Visa the last couple of times I've used these certs. Don't know what they would have done if I hadn't been able to produce the Visa. And the one time I used a cert with someone else's name on it was when I was buying tickets for the two of us to fly together. They did tell me that I could use a cert with my name on it to buy tickets for two other people, but that I would have to go to a ticket counter myself to do this.

Of course I don't know how often people succeed in bending the rules. Anyone?