What does 'SD' mean on the washer display?

The 'SD' code indicates that excessive suds were detected and a suds routine has automatically started to remove extra suds and ensure proper rinsing. The 'SD' code is displayed during rinsing and at the end of the cycle to inform you the Suds Routine was activated. To prevent this, use only HE (High Efficiency) detergents. (Page 22)