Treble (US) / Double Treble (UK)

US terms: Treble or Triple Crochet (trc)
UK terms: Double Treble (dtr)

Usually marked by a T-shaped symbol with two crossbars on the stem.

How-to:

We yarn over the thread twice. We insert the hook in the crochet piece and crochet the first stitch. We have four stitches on the hook. We crochet the first two stitches together. We have three stitches on the hook. We crochet the first two stitches together. We have two stitches on the hook. We crochet the first two stitches together again. We have two stitches on the hook. We crochet them together and get a triple crochet stitch.

If this is our first stitch in a row, we must remember to inserting the hook in the fifth stitch from the hook so as to gain the right height without misshaping the crochet piece. The remaining stitch is a turning stitch.