Question: "How can I limit which file formats are displayed by the print dialog?"
Formats can be registered and unregistered via code.
Example:
uses
ppDevice;
{add some file formats}
ppRegisterDevice(TppTextFileDevice);
ppRegisterDevice(TppReportTextFileDevice);
ppRegisterDevice(TppArchiveDevice);
{remove some file formats}
ppUnRegisterDevice(TppTextFileDevice);
ppUnRegisterDevice(TppReportTextFileDevice);
ppUnRegisterDevice(TppArchiveDevice);