Learn in the textbookPhysical Security Measures
DefinitionClear desk is the practice of leaving no papers or storage media on the desk when you step away or go home.
ExplanationDocuments and USB drives not in use go into a locked drawer or cabinet. Papers left out on a desk can be read or taken by anyone walking past.
AnalogyIt is the same as not leaving your wallet or notebook on the table when you get up from a library seat.
Memory hookClear (nothing on it) + desk. The name simply describes the tidied desk.