From applicable formations in which the Outside 4 can Circulate, such as
  Parallel Lines, Galaxy, Hourglass, Twin Diamonds, Thar, etc.
Centers do the anything call (working in the Center) as the Outside 4 Circulate.
Ends in various formations.
 CONTRAST THE FOLLOWING (assuming Twin Diamonds):
- 
  Lines Swing Thru:
  - Ends Circulate as Centers Swing [A2].
 
- 
  Lines Swing Thru Thru:
  - Ends Circulate as Centers Swing Thru.
 
 CONTRAST THE FOLLOWING (assuming Twin Diamonds):
- 
  Lines Ah So Thru & Roll:
  - Ends Circulate as Centers Ah So; everybody Roll.
 
- 
  Lines Ah So & Roll Thru:
  - Ends Circulate as Centers Ah So & Centers Roll.