This reports the configured signaling mode, a BITS-specific electrical/framing parameter, for this reference unit, and per the description is only meaningful when this particular unit is actually a BITS feed rather than some other reference type like GPS. An admin troubleshooting a BITS-fed unit that isn't achieving lock should verify this mode setting matches what the upstream BITS clock is actually configured to send, since a mode mismatch is a common cause of a physically-connected but unusable BITS reference. For example, this object being set incorrectly relative to the upstream source's actual output mode would prevent the receiving equipment from properly decoding the timing signal even though cabling is intact.