This reports the configured signal format, typically a framing standard like ESF or D4 for T1-based BITS feeds, for this reference unit, applicable only when the unit is a BITS-type reference, and it must match the upstream BITS clock's actual output format for the unit to lock properly. An admin connecting a new BITS feed and finding the unit stuck in an unlocked or acquiring-lock state should check this format setting against the BITS source's documented output configuration before assuming a cabling fault. For example, a unit configured for the wrong framing format relative to its upstream source would fail to synchronize even with a perfectly good physical connection.