A hairpin is a sharper or over turned Curvedfeather. A hairpin is nornallly used if sycopation is used as in pivot to hairpin. Here is an example for man in closed position facing line of dance with right foot free. Begin with one right turn, (now to begin pivot to hairpin) - step back with left foot and pivot one half, and do a sharp curved feather to outside lady and facing at least RLOD. After the pivot the next step with the man's right foot is between the lady's feet and, of coure you end on the balls of both feet lowering into the next step - could be back feather. The toe- heel is as with curved feather and the first step is normal pivot. The timing can be varied to suit individual choice. Common is 12&3, but one can use 123&, or 1&23.