The underarm shaping for this sweater is done using raised/lifted increases on each side of the front and back, at least that’s what the pattern implies. It says, “Work increases as k2, k1 in left side of st below, k across to last 2 st, k1 in right side of st below of next st, k2”. Although this is the first time I’ve used raised increases, this description just didn’t seem right. After checking several sources, I confirmed that the pattern incorrectly mentions which side of the stitch from the previous row to raise. Here’s how I’m doing it.
Increase stitch count by raising one side of a stitch from the previous row. These increases will slant to the left or right depending on which side of the stitch is raised. At beginning of next knit row knit two stitches. Now add a new stitch by using the right needle tip to raise the right side of the stitch below the one on the left needle onto the left needle. Knit this new stitch. Continue knitting across the back/front side of the garment until two stitches remain on the left needle. Now add another stitch by using the left needle to raise the left side of the stitch two rows down from the stitch on the right needle. While this new stitch is on the left needle knit into backside of it so that it doesn’t cross. Knit the next two stitches to finish the row. Note that the left increase is raised from the second row from the needle so that the increases end up on the same row.
While The Principles of Knitting has the best description and diagram of this increase I also found a good description in the Fall 2003 issue of Knitter’s magazine.