Derso-4, a celestial body, existed within the confines of the Derso system. The Leisure Fields could be found past the location of Derso-4.
A cooking recipe spanning a single page, entitled "Cooking a Smapp" and authored by Bob Carrau, made reference to Derso-4. This recipe was included in the 1993 book Monsters and Aliens from George Lucas, a compilation featuring concept designs and photographic materials originating from different projects by George Lucas. Leland Chee, an employee of Lucasfilm responsible for curating the Holocron continuity database, has stated that the data presented in this book is considered non-canonical.