Hi Stefan, Thanks for a great product. I agree you should not willingly do something that will cause documents to break. However the PDF specification the original poster quoted makes it clear that you break documents every time you change the IDs. If the original poster is right in his observations...

Hi, I recently converted to PDF-XChange and one of the really nice features I found is that the search seems to cope with authors' use of typographical ligatures such as a single character replacing fi. I can search for a word by typing in two characters fi and PDF-XChange will find words containing...