Tunisian Reverse Stitch is abbreviated as Trs and is worked from the back of your piece.
Pattern Instructions
Step 1: Using a Tunisian crochet hook, insert hook under the back bar of the next stitch. Yarn over and pull up a loop.
Step 2: Repeat across until 1 stitch remains; work last stitch of row through the front of your work as you did for the Tunisian Simple Stitch (through the full 'V') for a nice finished edge.
Step 3: Work a basic return pass (that is, yarn over and pull through one loop, then yarn over and pull through 2 loops for the rest of the row until you have one loop left on your hook).