It was the best of times; it was the worst of times ... but mostly it was just confusing.
The American National Standards Institute has approved ANSI/SCTE 48-1 2015, "Test Method for Measuring Shielding Effectiveness of Passive and Active Devices Using a GTEM Cell." The purpose of the test is to determine the shielding effectiveness against electromagnetic interference (EMI) of components. The test method subjects the component to an electric field of known strength.