This is a potential security issue, you are being redirected to https://csrc.nist.gov.
A BLACK metallic wireline that directly leaves the inspectable space in a continuous electrical path with no signal interruption or isolation. Continuous wirelines may be patched or spliced. Examples of wirelines that directly leave the inspectable space are analog telephone lines, commercial television cables, and alarm lines. Wirelines that do not leave the inspectable space are wirelines that pass through a digital switch or converter that reestablishes the signal level or reformats the signaling. Examples of BLACK wirelines that do not directly leave the inspectable space are telephone lines that connect to digital telephone switches, Ethernet lines that connect to digital network routers and alarm lines that connect to an alarm panel.
CNSSI 4009-2015 from CNSSAM TEMPEST/01-13