"%p -s -s -s -%t \"%f\""
"Format of command used to read EXIF data.
Available options are %p which is replaced by
-`image-dired-cmd-write-exif-data-options', %f which is replaced
+`image-dired-cmd-write-exif-data-program', %f which is replaced
by the image file name and %t which is replaced by the tag name."
:type 'string
:group 'image-dired)