enableFontSubstitutionWarning parameter
This parameter determines whether a warning message is displayed when the viewer needs to substitute fonts in a document of a type that uses system fonts.
Set this parameter to true to display a dialog box that prompts the user for how to proceed and render the document.
This warning message that is displayed depending on the allowDocumentFontSubstitutions parameter. If the allowDocumentFontSubstitutions parameter is set to true, the message states that substitutions were made. If this parameter is set to false, the message states that it truncated the document at the page before the first substitution was made.
The default value for the enableFontSubstitutionWarning parameter is false.
Example
<param name="enableFontSubstitutionWarning" value="true" />