When you click a file type group entry on the page, the Edit File Type Group Entry dialog box is displayed. You can change the MIME type, the file type, and the file type configuration for the entry.
When the value of the File Type selection for a MIME type is “Not Translatable”, the “File Type Configuration” column is blank for that entry. If the file type resolution process finds that a MIME type is set to “Not Translatable,” it treats assets of that MIME type as not translatable.