[mrmikel]

I think you are right Jelby. The error rates I found refer by character. That only makes close proofreading more imperative and almost word for word examination is required. Close guesses will work much of the time, but when they don't the whole meaning of the sentence is easily changed.

Columns are a particular bugbear. It is very common for parts of paragraphs to be shifted down the page and it can be remarkably hard to spot in casual reading. The tops of pages where the text in the right column is only a line or two is where it often happens.