M1Rpw (Right-leaning increase purlwise)

This increase will give the same result as M1R (worked on the right side), but it is worked on the wrong side.

Slip the point of the left needle under the yarn between the stitches from back to front.

Purl through the front strand. You have increased 1 stitch.

M1Lpw (Left-leaning increase purlwise)

This increase will give the same result as M1L (worked on the right side), but it is worked on the wrong side.

Slip the point of the left needle under the yarn between the stitches from front to back

Purl through the back loop. You have increased one stitch.