Set to 0 (zero) The image frames are not visible and they are not plotted
Set to 1 The image frames are displayed and plotted
Set to 2 The image frames are displayed but not plotted
Well, with the ability to now reference PDFs into drawings there is a new variable that does the same thing for PDFs. The variable is PDFFRAME
Set to 0 (zero) The PDF underlay frame is not visible and it is not plotted
Set to 1 Displays the PDF underlay frame and allows it to be plotted
Set to 2 Displays the PDF underlay frame but keeps it from being plotted
