Final answer:
The minimum clearance rearwards of the anti-intrusion plate to the test fixture in IA testing refers to the space needed behind the plate to accommodate the fixture.
Step-by-step explanation:
The minimum clearance rearwards of the anti-intrusion plate to the test fixture in IA testing refers to the distance needed behind the plate to accommodate the fixture. This clearance allows enough space for the test fixture to be properly positioned and secured. The specific minimum clearance required may vary depending on the specific testing equipment and requirements.