Right side of work facing you, working left to right,insert hook in next stitch to right,then Yarn over,draw yarn through stitch,draw yarn through 2 loops on hook and repeat again
A reverse single crochet is done where you insert the hook to the right. So instead of moving right to left, you'd make your single crochet left to right.
Reverse single crochet is also known as Crab Stitch. Instead of crocheting from right to left, you crochet into the stitch left of where you just worked. It forms an attractive decorative edging. There are several videos on youtube demonstrating this stitch clearly.
Working left to right, insert hook in next stitch to the right, yarn over, and draw thread through. Thread over, draw it through two loops on hook. One reverse single crochet completed! This is also called a 'crab stitch'.
The technique is the same as for a regular single crochet, only this time it is done in reverse, if you want to do it you should work from left to right.