From a squared set: Heads Star Thru, Pass Thru then with the sides Pass Thru and (heads only) California Twirl. Sides in the middle do a Star Thru, Pass Thru and California Twirl.
Twice thru the routine gets everyone with partners but in opposite position. Four times through gets everyone back home with partners.
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.