Here's another definition of knot stitch - http://www.knittingonthenet.com/patterns/swespring.htm
"(make knot) Insert right needle under
thread between next 2 sts
on left needle, wrap yarn and loosely draw up a loop and place on right needle. Insert right needle above
same thread and loosely draw up a second loop and place on right hand needle. With yarn in front, p first st from left needle. Pass first loop over second loop and p st, then pass second loop over p st-knot made"