Not sure what this is actually about, but if it's for basting then there is an explanation of using basting in the manual. Basically as far as I remember it's in the quilting application (could be wrong on that though) Think it drops the feed dogs and suggests the foot to use. You move your quilt to where you want to make a stitch, press the foot pedal and it makes one stitch, then move your quilt to where you want the next basting stitch, press the foot pedal and it makes another stitch - then continue.
It's something I've yet to try. I really wish I could find a new machine that does what I call a true basting stitch like my old Elna Diva - that can be set to do a basting stitch every 13 mm - brilliant - though both my Elna and 15000 are currently at my step daughters while we try to progress our move.
"With all its sham, drudgery and broken dreams,
it is still a beautiful world. Be cheerful. Strive to be happy." Max Ehrmann