The Front Post Stitch (FPdcif) and the Back Post Stitch (BPdcib) are normal post stitches executed in the Interlocking Crochet™ technique. They create columns on one side of the fabric and vertical chains on the other side of the fabric. This design is created by alternating rows of Front Post Stitches and Back Post Stitches. The design is found on page 58 of the book, Interlocking Crochet.