kyok2tog
Knit two stitches together as if they are one stitch, but before dropping the stitches off the left needle, work a [yo, k] into them.
Stitch count increases by 1.
sskyok
Slip two stitches separately knitwise, then work a kyok into them both.
Stitch count increases by 1.
k2togm1
Knit two stitches together, then knit one into the stitch below the stitch just worked.
Stitch count does not change.
m1ssk
Knit one into the stitch below the next stitch on the needle, then work a ssk.
Stitch count does not change.
cpdd
Slip two stitches together, knitwise, place them back on the left needle, then purl three stitches together through the back loop.
Stitch count decreases by 2.