Hernalt wrote The simplest explanation is that it is possible Kahn extrapolated from Lucas’ “enemy ships at Sector RT-23 and PB-4” and embellished it with “two behemoth flanking waves”. This simple explanation doesn’t answer why there was a battle outside the Emperor’s window, and other select inconsistencies. Alternatively, it could also be that “enemy ships at Sector RT-23 and PB-4” were Kahn's embellishing the "two waves" as these two sectors only showed up in the novelization, but none of the (additional) genuine Ackbar screenplay lines at our disposal. Had Kahn merely made up the whole thing, I don't believe he would provided a description of the briefing room aboard Ackbar's ship with the hologram revealing the two waves. He could have skipped that, and that's why I remain confident we are looking at a hologram VFX for the briefing room that just never made it. So if Rinzler was accurate, Vader once arrived in an SSD, at least in concept art. That has a resonance with the scene header in the sanitized script where the SSD with Piett on it is called “VADER’S STAR DESTROYER”. If Vader was intended by Lucas to arrive at the DS2 in a SSD, then that conception precedes the scripts given to Kahn, because Kahn has him arriving in an “Imperial Star Destroyer”. This would be another time where I'd suggest caution to draw "in-universe" conclusions from a script that had been always first and foremost intended for production purposes (compare to the example I provided in the Star Destroyer Bridge thread: http://boards.theforce.net/threads/...riginal-trilogy.50044307/page-2#post-54162253 ) "Vader's Star Destroyer" was ILM's description for any scene that involved this particular VFX model and all the script does here is to give the guys at ILM a heads-up that this particular model will be needed in a couple of shots (that the Super Star Destroyer that crashed into the Death Star was the Executor is a conjectural idea that originates with Mr. Zahn - I had a personal discussion with him at an Italian SW convention where he expressed his personal dislike for a ship like that, feeling there should only be one despite Solo's suggestion to the contrary and the explicit script annotation "Emperor's Super Star Destroyer"). Of course, that does not answer the question why it says in some scene headers "Vader's Star Destroyer" and in others "Super Star Destroyer". Either that's a hint that two Super Star Destroyers were originally considered for the space battle (and mixed up) or Lucas decided to give the VFX model finally another description ("Super Star Destroyer") but ultimately wasn't consistent in doing so.