Ishanna inversion

"Home One was close behind it, as I recall. Did we beat Meeta Cors' Nautilian out of stardock?''" "''A prescient comment. The ship's brittle construction ultimately hampared its rollout, particularly after the Ishanna inversion."

- Admiral Gial Ackbar, and U.O. Statura in an annotation on The Rebel Files

The Ishanna inversion was an event that hampered the delicate construction of the Nautilian while going combat refit in the Telaris rebel stardock during the early rebellion against the Galactic Empire. In 34 ABY, after The Rebel Files were recovered, Resistance Admiral Gial Ackbar left an annotation on a report in the files commenting on whether his Home One ever beat the Nautilian out of stardock. Fellow Admiral U.O. Statura left a reply, stating that its construction was hampered by the Ishanna inversion.

Behind the scenes
"It’s newly invented for the book, so speculate away. Ishanna is a star system from “Combat Moon,” a short story in the old SW Adventure Journal."

- Daniel Wallace, on twitter

The Ishanna inversion was first mentioned in Star Wars: The Rebel Files, a canon boxed set and reference book authored by Daniel Wallace and released in 2017.