Re: And this ladies and gentlemen...
This harks back to something we did early in the computer days, where you were required to write a zero with a diagonal cross in it to eliminate the confusion with capital O's. We also had to put a horizontal dash across any 7s, so they wouldn't be confused as the number one (1). I kept that habit for decades afterward, and it actually came in handy when I ended up in military supply, and using coded entries so the computer could read the difference as well.
Ah the memories of those good ol' days! First it was to help keep from confusing the keypunch operator, and later the optical computer reader - either way, it helped end the confusion - Oh and the numeral one looked like an upside down capital T! Ah yesss!