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
Star Wars: From the Adventures of Luke Skywalker before the film was released, the novelization sold out its initial print run of 125,000 copies. In the next three months, Ballantine had sold 3.5 million copies. Some later editions contain sixteen pages of full-color photos from the motion picture. Later editions of the novelization were published under altered titles to reflect the retitling of the film, such as "Star Wars: A New Hope", and "Star Wars IV: A New Hope". The words that open each "Star Wars" film, "A long time ago in a galaxy far, far away..." are absent from the novelization, substituted by the similar "Another galaxy,