I was wondering why some PDF documents compiled from some LaTeX code does not make its text correctly copyable, i.e. what you can get is nonsense text? For example, this pdf document (I don't have the LaTeX code for it).
The PDF specification allows for this - displaying something different from what is retrievable. The
Another example of this provided by the
For an example of this, see How to make text copy in PDF previewers ignore lineno line numbers?
The motivation for this is most certainly security, as is motivated from the
Perhaps, more useful would be asking what to do to avoid such troubles. If so, then awswer is to load