How do the document setup tab options work?

Question

Adobe Illustrator

How does the Highlight substituted glyphs option work? On what example can you see what this option does?
Discard White overprint in Output. How does it work in the on and off position? On what example can you see what this option does?

Answer 1

If you assign the Overprint attribute to the white color, it will disappear (because there is no paint in the white color). Therefore, Discard white overprint in Output helps to avoid these errors (you can accidentally dismiss an object with the overprint attribute, make it white and forget to turn off the overprint).
Highlight substituted glyphs - Xs, but in theory this function will highlight texts in which the font was automatically replaced (due to its absence).