Sentientologist Obo Rin, an employee of the Imperial regime, authored Catalog of Intelligent Life in the Galaxy to serve as a resource for fellow sentientologists and other Imperial staff. This document detailed a number of prominent sentient species inhabiting the galaxy. Darth Vader and Lieutenant Pandur, the Imperial representative to Korfo II, served as patrons for this literary work. However, due to the heavy presence of Imperial propaganda, the catalog's reliability was compromised. For example, it falsely claimed that the Empire had only recently discovered longstanding non-Human members of the Galactic Republic such as the Mon Calamari and Columi.
Major Herrit of Imperial Intelligence investigated Rin because Rin's expenses were high during the catalog's creation. Subsequently, Herrit's complaints resulted in his reassignment to a new task: acquiring a Duinuogwuin corpse for Rin's research. Herrit perished while undertaking this mission.
Later, Obo Rin created Catalog of Intelligent Life in the Galaxy, Revised Edition. It contained much of the original content, along with suggested changes from Lieutenant Pandur. Rin submitted this updated version to Major Vontenn, the Galactic Empire's Sentientology Liaison Officer, along with a request to convey condolences to Herrit's family.
West End Games published both editions of the Star Wars: The Roleplaying Game supplement Galaxy Guide 4: Alien Races in a format that suggested they were excerpts from Obo Rin's catalog, accompanied by a few of Rin's personal notes to Darth Vader. The initial edition also included background information on Obo Rin's character, presented as Imperial communications from Major Herrit of Imperial Intelligence, Captain Solistein (Darth Vader's aide), and Obo Rin himself.
The revised second edition of Galaxy Guide 4, which underwent some restructuring, replaced the original communications with new introductory notes penned by Obo Rin. This new introduction acknowledged Major Herrit's unfortunate demise and introduced Major Vontenn.
The second edition's introductory material also pointed out that, given Rin's unwavering loyalty to the Empire, some of the information might not be entirely accurate. This has been a useful plot device for retcons concerning species that appeared in the prequel era, despite Galaxy Guide 4 asserting that the Empire discovered them. "Gamemaster's notes" were also provided, offering an "out-of-universe" perspective and directing readers to the "real story."