This is very similar to Tunisian Simple Stitch, the main difference is that you work through the rear posts of the work rather than the front.
Despite what you might think it doesn’t fully reverse the appearance of the sides when compared to Tunisian Simple Stitch
Tunisian Reverse Stitch starts with a Foundation Row
Start by putting your hook through the 2nd vertical loop at the rear of the piece and pull a loop through. Continue along the work pulling loops through every vertical post until the end.
Complete by working a standard Return Row.