Left Diagonal Rib

Knitted in a multiple of 6 sts and a 12-row repeat.
Row 1 - RS: *P2, k4; rep from * to end.
Row 2: *P4, k2; rep from * to end.
Row 3: * P2, k4; rep from * to end.
Row 4: *P4, k2; rep from * to end.
Row 5: K2, *p2, k4; rep from * last 4 sts, p2, k2.
Row 6: P2, *k2. p4; rep from * last 4 sts, k2, p2.
Row 7: K2, *p2, k4; rep from * last 4 sts, p2, k2.
Row 8: K2, *p2, k4; rep from * last 4 sts, p2, k2.
Row 9: *K4, p2; rep from * to end.
Row 10: *K2, p4; rep from * to end.
Row 11: *K4, p2; rep from * to end.
Row 12: *K4, p2; rep from * to end.

Knitting abbreviations:
Knit: K | Purl: P.