This is the part that I'm having trouble understanding:
Using MC, CO 84 (100, 116) sts. (WS) Purl 1 row.
Begin Elongated st patt and Stripe Sequence, and AT SAME TIME, shape center Front and center Back EOR as follows:
All (RS) rows: K1, k2tog, knit across to 2 sts before marker, k2tog, slip marker, k2tog, knit across to last 3 sts, k2tog, k1.
All (WS) rows: Work even in patt.
Work 28 (34, 40) rows total in Elongated st patt, ending (WS) Row 4—28 (32, 36) sts rem for neck.
(RS) BO all sts loosely purlwise.
So, I know how to cast on the stitches, and purl. Also, I can figure out the elongated st patt and stripe sequence, but the part, "at same time, shape center front and center back EOR as follows..." I don't understand.