M1L (Make 1 Left)
M1L is an increase technique that creates a new stitch by lifting the strand between two stitches and knitting it twisted, so the increase slants left.
Explanation
M1L (make one left) mirrors M1R. You lift the strand between stitches from front to back and knit into the back loop, twisting the new stitch so it slants to the left. Because both techniques are nearly invisible, they are often used together: M1L on the left side and M1R on the right side of an increase line, such as at raglan lines or sleeve increases, giving the garment a symmetrical, professional look.