Here's a link to the Ravelry page. The idea here is that as you knit the border, you're also attaching it to the body of the shawl. It seems that for your pattern, this is done by knitting 2 together at the end of the border RS row. Then turn, purl to the end of the border, turn and knit towards the shawl body ending again with k2tog to join the border and shawl body. Continue this until there are only 2 shawl body sts left. On the RS row k17, skp, turn, knit back, turn and repeat.