Not sure how they work... But its on trial now. In some ways its good for 22 year olds (like me) who always get asked for ID when purchasing a hard drink but then my license already does the job.
And these days clubs and bars seem to be asking for ID a lot more and they want something with a photo on it. Sure, we carry our passport with us.. As if! The other is a driving license, but not everyone drives.
I remember once I showed my license as ID when I went to a bar, this **** looked at it and said but your date of birth is 1999 - I said to her - Do I look like I was just born? Stupid!