Zip Code 1-6

From any 2x4 formation with the centers in columns (e.g. double pass thru or eight chain thru): Centers Quarter Out (forming a momentary T-bone) and Run around the outsides [=Zip Code 1], Pass Thru [=Zip Code 2], Ends Bend [=Zip Code 3], Pass Thru [= Zip Code 4], etc. As this happens, the original outsides move into the center, without turning. Odd numbers give facing ends; even give back-to-back ends.