It takes a highly trained eye to catch a zero that should be the letter O, and vice versa, when proofreading. Another such error is mistaking the numeral one (1) for a capital I or a lower case L, depending on the font used. This former is more common, because the 0 and the O are very near each other on the QWERTY keyboard.
Now, when reading a report with such errors, most people will gloss right over them, not noticing the minute differences, if any. The brain sees what it wants to see in this
case. However, in the Digital Age, search engines will not be able to locate the paper online if the title says 0klahoma instead of Oklahoma.
In an Excel spreadsheet, substitution of the letter O for zero will turn a number into a
word (Example: 2o11) and could create justification issues or calculation errors. Here, a lower case L or upper case I causes the same problem when it’s supposed to be the number one. This can happen frequently if optical character recognition (OCR) is performed on text or numbers scanned into the computer.
There is no easy fix I know of for this sort of error. Anybody out there in the Peanut Gallery know any tricks?
Let me just say that you should be cognizant of the possibility, and if you see a zero that looks too fat or an O that looks to thin, you’ll go ahead and fix it.