This version of a inc3 is a knitting technique to increase from one stitch to three stitches by knitting into the front and back of one stitch.
(K-fb version) Knit into back leg of stitch, then without removing stitch from left needle, knit into front of stitch, then into back of stitch and remove from left needle. Increases to 3 stitches from 1 stitch.
See also: inc3 (IncR & incL version)
