Camouflage field
A camouflage field was a type of shield technology used by smugglers. These fields camouflaged contraband from cargo inspectors by generating false sensor readings.
In 2372, Michael Eddington described a scenario to Kasidy Yates and Benjamin Sisko where inspectors, working under the ruse of a health inspection, had the time needed as they looked for camouflage fields, false cargo manifests, and computer records. (DS9: "For the Cause")