The better question is why is 0 next to O. How many programming bugs have resulted in 0 and O being so close together on the keyboard.

Probably 0. :)

How often do you see a variable named "O"?

"To tell them apart", a former coworker used the variables named:

     style1
     stylei
     stylel

Ironically, they were still there for some time after I'd left.

I'm reminded of the brilliant How To Write Unmaintainable Code.