Oh, I think that I see what you're asking - the first marker for the left front is 30 stitches from the left sleeve edge (third paragraph after the heading Left Front on page 4)
The marker for the Right Front is 28 stitches from the right sleeve edge. (Second paragraph after the heading Right Front on page 5)
On the RS you will knit to the marker, slip the marker, then slip 2 stitches purlwise, then slip the next marker. You are now 30 stitches from the right edge. You will knit to the next marker, 30 stitches from the left edge, slip the marker, slip 2 purlwise, slip the next marker and then knit 28 stitches.
The 18 stitch notations are for both sides of the back as far as I can see. (page 3)