This group is automatically enabled or disabled depending on the output device you selected ("on" list box). This group is enabled only if you select a "device" that does not output to paper or to an imagesetter but writes to a file. "Devices" with file output in the "FormProof" sequence are softproof processors that can be named, for example, "SoftProof", "PDFExport", "TIFFProof" or "JPEGProof".
"MIME Type" box
The "MIME Type" (Multipurpose Internet Mail Extensions) box shows the format of the output files.