short for Black and WhiteProcessing: processing in which the auditor gets the preclear to get a current flow to run. The preclearcan see the flow. As long as it's flowing, it's white, and when it is not flowing anymore, it looks black. So you flow it in one direction as long as it will flow white. And then it turns around and flows back as long as it will flow white. —PDC 2 Approved Glossary