Exhibit A: a toilet door in a government office.
Exhibit B: Can't help feeling there's a story behind this one.
Exhibit C: this Lufthansa check-in machine had two of us foxed for a while. The problem is that the Reservation Code is a list of numbers, but there are no number keys shown. It turned out that the number keys appear once you place the cursor in the right box. But we didn't get that far before bothering the airline helper.