In DOT numbers how can I tell the difference between 0 (zero) and O (capital o)? Most fonts used on tire sidewalls make them difficult to tell apart, and I can't find any rules online saying that capital O's aren't used, so I'm left to guess on a case-by-case basis. I know the last four digits are numbers-only because they tell when the tire was manufactured, but on all tires I've seen any zeros in the last four digits are indistinguishable from the capital O in "DOT".
It's very important to keep accurate record of DOT numbers in my line of work (winter tire traction testing), but unfortunately I haven't been able to find anyone who can really help me with this issue.
Also sorry if this isn't the right forum for this question, it was the first forum I found where I thought people might know the answer.