(B) Clear Spaces. Working space required by this sectionshall not be used for storage. When normally enclosed liveparts are exposed for inspection or servicing, the workingspace, if in a passageway or general open space, shall besuitably guarded.
Above is the actual code...not exactly as Mr. Holt states. Again sometimes we know that personal preference or opinion can taint the verbiage as it is written. That is why it is important to understand that teaching material or handbooks are simply opinions.