In english books, you can read it like this... hdc .
In an international book that uses symbols, read it like this or you may see it to be this way ....
A half double crochet or hdc is slightly taller than a single crochet. This stitch is the first of the basic stitches that requires a yarn over before you insert the hook.
Step 1: Place the yarn over the hook and then insert the hook through the two upper strands of the stitch to be worked.
One loop remains on hook. One half double crochet made.
When working half double crochet on the next row, always chain 2 (2 chains count as your first half double crochet), then turn, skip first stitch and start your second half double crochet in the stitch.
When working the first row of the half double crochet (hdc) on the foundation chain, start your stitch in the fourth chain from the hook (3 skipped chains count as your first half double crochet, 1 skipped chain count as foundation chain).