Part 2 (May 2022), https://incompliancemag.com/article/scif-and-radio-frequency...

> Whether it is used for power, communication, data, or building management systems, a component than includes or uses conductive cables or wires needs to be filtered to maximize the RF performance of a shielding system ... If it is conductive, it has the ability to carry signals and radiate similar to an antenna. Similarly, critical or protected signals are at risk of coupling to those cables or wires and leaving the secured space ... a cost-effective solution may be to use fiber-optics in the secure space that can penetrate the shielding through an inexpensive RF waveguide or series of RF waveguides.