From a completed double pass thru formation: Leads do a Partner Tag, then Partner Trade with the one from the other side who also Tagged, staying well apart. Meanwhile trailing couples Partner Trade, Partner Tag and then do a Centers In. Finishes in lines with centers facing out and ends facing in.
Bill Barton 1973
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.