How do I use the stitch length dial, and what do the settings mean?

The numbers marked on the stitch length dial represent the stitch length in millimeters — the higher the number, the longer the stitch. With the '0' setting, material is not fed, which is used when sewing a button. The 'F' to '1' range is for making a satin stitch (closed zigzag stitch), used for buttonholes and decorative stitches, and the exact position should be tested on a scrap piece of fabric first. (Page 1)