From the Stitch Description: The Cloverleaf Eyelet is beautifully adapted to vertical patterns, such as the Cloverleaf Eyelet Rib and Cloverleaf Eyelet Cable. In this Rib variation, the pattern could be widened by working on a multiple of 7 sts plus 2, inserting 2 purl sts between ribs instead of one.

Location of Stitch: Page 170 from A Treasury of Knitting Patterns.