"1/200 - 80 mm" if there's no ISO information in the Exif data.
If a line is empty, it is removed.
- This allows one to add lines that totally disappear when no data is available.
+ This allows to add lines that totally disappear when no data is available.
Extra string uses special character '*' to mark the position of the data.
If no '*' is present, then extra string is just appended to data.