[Lorento]

I have a pdf scan of a text book that exibits this problem. It's a complex math book with a lot of superscripts, subscripts and combinations of them. Some are the wrong symbol - eg i instead of j, etc. It was very difficult to study from not being able to trust any symbol. I put it down to bad editing of the printed original until I found out about this story sometime ago.

[userbinator]

One of the links in the comments of the original post has a good example of that:

http://everist.org/NobLog/20131122_an_actual_knob.htm#jbig2

(JBIG2 discussion near bottom, rest of page is about electronics.)