wyif or with yarn in front
This is telling you where your yarn should be before performing the next technique or stitch. With yarn in front refers to the location of the yarn vis-a-vis the needles, so whether it is wrong side or right side it is always in relationship to the needles.
Working on the right side: wyif or with yarn in front places the yarn is in front of the needles, on the right side.
Working on the wrong side: wyif or with yarn in front places the yarn in front of the needles, on the wrong side.
For the opposite, see WYIB or with yarn in back.