Unembed all fonts
A PDF file does not necessarily have to contain all used fonts.
If a font is used inside a PDF for a text, it is referenced by its name. The font can either be contained - then the contained font is usually used when the PDF is displayed, or cannot be contained - then the respective PDF viewer can search for a font with the referenced name on the system, and (if such a font is not found) use another font for displaying the text.
Starting pdfToolbox 13, it is now possible to remove all embedded fonts from a PDF file.
The Switchboard action 'Unembed all fonts' has no parameters and will simply remove all embedded fonts from a PDF file.