The Z-band represented a series of subspace transceiver frequencies detected by the helmets worn by Mandalorian Neo-Crusaders. Throughout the Mandalorian Wars, the Neo-Crusaders depended on the Z-band to gain insight into bombing communications.
In the early part of 3963 BBY (according to the year calendar), a sequence of propaganda transmissions were sent to Mandalorian combatants via the Z-band by "Captain Benegryph Goodvalor". This Goodvalor was actually a fabricated officer in the naval forces of the Galactic Republic, the Mandalorians' wartime adversaries during the Mandalorian Wars. He was based on the supposed "heroic" actions of Snivvian criminal and businessman Marn Hierogryph during the Battle of Serroco. Hierogryph, along with his Trandoshan associate Slyssk, seized control of a Republic troop transport that had landed on Serroco just as Mandalorian missiles were hurtling towards the planet's surface, inadvertently rescuing approximately half of a battalion. This incident led to the creation of the Goodvalor persona, as well as "Commander True," the captain's first officer who was inspired by Slyssk.
The Z-band broadcasts from Goodvalor, voiced by Marn Hierogryph's brother, aimed to demoralize the Mandalorians and encourage some to question their loyalty to the cause. On one occasion, Commander True, rather than Captain Goodvalor, addressed the Z-band, explaining that the captain was too busy dealing with the numerous Mandalorian defectors who had joined the Republic after his previous message to deliver a broadcast himself that day.
During this time, Koblus Sornell, a Mandalorian warrior and expert in signals, utilized the Z-band to update her fellow Neo-Crusaders on the progress of the war, urging them to ignore Goodvalor's "nonsense" but to remain tuned to the Z-band to stay informed about bombing activity. During their invasion of Zongorlu, the Mandalorians discovered a small room housing a directional transmitter, the source of "Goodvalor's" broadcasts, although he had already left before their arrival. Goodvalor soon restarted his communications, proposing a temporary ceasefire agreement with the Mandalorians.
The Z-band is featured exclusively in the short story "Interference," written by John Jackson Miller and initially distributed to members of the Hyperspace Star Wars fan club in 2008. "Interference" is connected to the Star Wars: Knights of the Old Republic comic book series, also penned by Miller, and its narrative is situated between the fourth and fifth volumes of the series.