Work in back back loop only of half double crochet

(When you work in round with right side of the work facing you.)

1. Here is an example of loop whose work normally (in front AND back loop)

2. For work on back back loop , work in the loop after the back loop.

3. Here is a view from above a stitch work in back back loop only.

If you need more help to work in back back loop only, you can see this video :