Doctor Who remnant shawl #2, half-octagon or semicircle: Part I

I'm totally winging this.  

It's a stockinette half-octagon or semicircle shawl with 5-stitch garter stitch border and knit front and back (KFB) increases.

Garter tab cast-on:
Cast on three stitches.  Knit all each row for nine additional rows.
Pick up and knit eight more stitches down the side and end of the tab (11 stitches total)

Row 1: Knit all
Row 2: K1, KFB, K2, KFB, PM, K1, PM, KFB, K2, KFB, K1 = 15 stitches
Row 3, and all WS rows: Knit 5, purl to last 5, knit 5
Row 4: K1, KFB, K3, KFB, SM, K1, SM, KFB, K3, KFB, K1 = 19 stitches
Row 6: K1, KFB, K4, KFB, SM, K1, SM, KFB, K4, KFB, K1 = 23 stitches
Row 8: K1, KFB, K5, KFB, SM, K1, SM, KFB, K5, KFB, K1 = 27 stitches
Row 9: K5, P1, PM, P1, PM, P6, SM, P1, SM, P6, PM, P1, PM, P6, PM, P1, PM, P1, K5

So, basically, on all wrong-side rows you knit 5, purl to the last 5, and then knit 5.

On every other right-side right-side row, you knit all.

On the other half of the right-side rows:
Knit 1
Knit front and back
Knit to one stitch before the first marker
Knit that stitch front and back
Slip marker
Knit stitch between markers
Slip marker
Knit the next stitch front and back
Knit to the last stitch before the next marker . . . etc.
Knit to last two stitches,
Knit front and back
Knit last stitch.