OOM command battle droids, OOM pilot battle droids, and security battle droids all had a different purpose. This was shown by their markings of a different color.
- —battle droids designed for security, also known as Specialist Droids. These battle droid were identifiable by the distinctive red markings on the back of the head and body. They were used in the Invasion of Naboo by the Trade Federation and were incorporated into the Separatist Droid Army, tasked to serve as security at locations like the prison the Citadel, or the Providence-class DreadnoughtInvisible Hand, and act as snipers and special infantry for battles against the Republic.
- —battle droids were designed to serve as pilots to control starships, such as the cruisers of the Confederacy navy. They can also pilot the hijacked Venator-class Star DestroyerRenown. These battle droid were identifiable by the distinctive blue markings on the back of the head and body. Pilot droids could also serve as gunners for artillery or, if they were armed with a blaster, be used as soldiers, though they were known to protest against serving in such roles.
- —battle droids were designated by their dull yellow markings on their bodies. The droids possessed enhanced cognitive and tactical modules, and were used to lead droid forces. However, the droids were often subservient to organicofficers or tactical droids, but in the absence of their higher officer an OOM command battle droid was able to take control of military forces.
The concept of the "OOM-series" was first introduced in Star Wars Legends for the Roleplaying Game, inspired by the designation of commander battle droid OOM-9. The series name was later brought into canon through Star Wars: Build Your Own R2-D2 30.
Star Wars: The Complete Visual Dictionary, New Edition stated the OOM-series was created before the B1-series. However, 2015's Ultimate Star Wars and 2019's Ultimate Star Wars, New Edition both contain battle droid pages that list the model as B1. Therefore, all information on the page applies to the B1 battle droid, but the section also mentions the security, pilot, and command droids that The Complete Visual Dictionary treated as predecessors. Additionally, both versions of Ultimate Star Wars state that OOM-9 is an OOM command battle droid and a B1. Another 2019 reference book, Star Wars Character Encyclopedia, New Edition, similarly included a battle droid page that listed the droid type as a B1, but it also included information on pilot battle droids. Star Wars Battlefront II and Star Wars: Droidography both also state B1s served as pilot droids. The battle droid Databank entry on StarWars.com does not mention a difference in model despite including information involving B1s and OOMs. Star Wars: The Rise of Skywalker: The Visual Dictionary later established that the OOM-series was a mark of the B1 line. Given that most sources establish that the OOM-series were a part of the B1-series, this article assumes Star Wars: The Complete Visual Dictionary, New Edition is incorrect.
- LEGO Star Wars: The Skywalker Saga
- Star Wars: On the Front Lines
- Star Wars: Build Your Own R2-D2 30
- Star Wars: Build Your Own R2-D2 31
- Star Wars Bust Collection 13
- Star Wars Bust Collection 13
- Star Wars: The Complete Visual Dictionary, New Edition
- Ultimate Star Wars, New Edition
- Star Wars: The Rise of Skywalker: The Visual Dictionary
- Star Wars Complete Vehicles, New Edition