ABBREVIATIONS:
Ch = chain
St = stitch
Sc = single crochet
Hdc = half double crochet
Dc = double crochet
BL or BLO = back loop / back loop only

NOTES:
This pattern can be made in any yarn size, type, or gauge and with any hook size. The ribbed effect is accomplished by stitching in the back loops only. The general design is a rectangle that is sewn together along the sides into a tube and then sewn/cinched at the top to form a hat! One side/end of the rectangle has a set of smaller stitches where the cinch will be, so that there is less material bunching at the top. This pattern is written with HDCs for the majority of the rectangle/the main stitch, and SCs as the smaller stitches for the cinch area/top of the hat. Alternatively, you can use DCs as the main stitch and HDCs as the smaller stitch. The hat will work up faster this way but will give a slightly different look to the stitching. It is up to you which look you prefer, but the pattern is written using hdc/scs.