Trace resonance signature
Referred to in the first draft script of the  seventh season episode , a trace resonance signature was a tell-tale technological sign that an isolinear chip had been altered.

In the aforementioned script, Chief Miles O'Brien told Doctor Julian Bashir that, if any of a particular set of isolinear chips in Starfleet Medical's main computer, which they were accessing from Deep Space 9's infirmary, had been altered, a trace resonance signature would be evident.
Unused production material