Clone trooper film series and in the "Star Wars" expanded universe media, a number of specialized trooper units are seen, including elite special forces units such as the 'Advanced Reconnaissance Commandos' (ARC troopers), and Null ARCs, who usually work alone. All clone commandos and ARCs were trained by Mandalorian mercenaries; the elite Clone Troopers are known as Shadow Troopers. The style and color of a clone troopers armor often varies depending on their rank, specialization, unit, or environment, for example, the clone troopers on Kashyyyk wear camouflage green scout-style armour whereas the 501st legion wears standard white armor with blue accents. Another
A Guide to the Star Wars Universe A Guide to the Star Wars Universe A Guide to the Star Wars Universe is a reference book based on the "Star Wars" franchise published by Del Rey. The first edition was published in 1984 and written by Raymond L. Velasco, while a second edition was published in 1994, written by Bill Slavicsek, who later also wrote a third edition, published in 2000. The books alphabetically detail fictional people, places, things, and events in the Star Wars expanded universe. Most of the entries are quite short, with the longest being just over two pages. Each entry is divided into "G-canon"