Squadron Four was one of the six squadrons that composed the 204th Imperial Fighter Wing. This fighter wing of the Galactic Empire was under the command of Captain Jothal Gablerone. The squadron embarked on a mission to Vnex, communicating their findings back to Colonel Shakara Nuress stationed on Orbital One. Later, during the attack on Pandem Nai, the squadron chased Yrica Quell and Chass na Chadic, who were New Republic pilots, but they were unsuccessful in their attempt to take them out.
The novel Alphabet Squadron, released in 2019 as the initial book in the Star Wars: Alphabet Squadron trilogy by Alexander Freed, referenced Squadron Four. Additionally, a squadron under Jothal Gablerone's leadership made an appearance. It was later established that Gablerone's squadron was indeed Squadron Four in Shadow Fall: An Alphabet Squadron Novel, the second novel in Freed's trilogy, which was published in 2020.