Half double (US) / Half treble (UK)
Half Double Crochet / Half Treble Crochet
US terms: Half Double Crochet (hdc)
UK terms: Half Treble (htr)
Usually marked by a T-shaped symbol.
How-to:
We yarn over the thread, insert the hook in the crochet piece and crochet the first stitch. We have three stitches on the hook and crochet them all together in one move. Now we have a half double crochet stitch.
If this is our first stitch in a row, we must remember to insert the hook in the third stitch from the hook so as to gain the right height without misshaping the crochet piece.