O, what a tangled web...

It's a constant cause of confusion - O - is that capital "o" or zero?  There was a time when zero was written with a diagonal line through - Ø - to make it clear, but that idea seems to have been abandoned.  Does it matter?  Well, it can be when you get these "prove you're not a robot" tests where you have to copy a line of letters/numbers and the question arises as to whether what you are being asked to copy is "o" or zero, but here's a case where it has potentially cost someone money. You know those automated carparks where you have to input your car's registration to get a ticket? Well a lady input her reg, except that she erroneously input capital "o" instead of zero and has now been hit with a £100 fine, and the parking company are refusing her appeal.  So be careful out there...