Deletion was what the Cybermen of Pete's World termed the killing of all those they deemed incompatible for the upgrade to cyber-form. The primary instruments of deletion were the hands of the cyber-suits, which were capable of transmitting a fatal electric shock to humans, (TV: Rise of the Cybermen/The Age of Steel) and projectile weaponry such as the cyber wrist blaster or energy blasters. (TV: Army of Ghosts/Doomsday) In N-Space, Cybermen used eradication. (TV: Silver Nemesis)
Deletion was similar to the creed of extermination followed by the Daleks, who the Cybermen engaged during the Battle of Canary Wharf. Like the Daleks, it was known for the Cybermen to exclaim "Delete!" before attacking. (TV: Doomsday)
In Pete's World, the first known victim of deletion was Dr Kendrick, a scientist in the employ of John Lumic, CEO of Cybus Industries and inventor of the Cybermen, that oversaw the creation and testing of the prototype Cyberman in 2007. When Kendrick informed Lumic that Geneva needed to be informed of its creation Lumic gave his first Cyberman the order to kill him, which it promptly carried out.
Following the orders of John Lumic, a group of newly upgrade Cybermen "crash[ed]" the 40th birthday party of Jackie Tyler where he, speaking from Cybus, introduced them to the assembled guests, among them the President of Great Britain, before leaving the party in the "care" of the Cybermen. When the President refused the compulsory upgrade program, the Cybermen deemed him to be incompatible and so used their electrified hands to "delete" him and majority of the party guests. While Pete Tyler escaped with the Tenth Doctor and Rose Tyler of N-Space, Jackie was captured and upgraded into a Cyberman. (TV: Rise of the Cybermen)
Mr Crane, originally Lumic's subordinate, was killed by the Cybermen for making an attempt on Lumic's life. Elsewhere in London, Ricky Smith and Angela Price of the Preachers were seperately killed by the Cybermen. (TV: The Age of Steel)
Commandeering Torchwood Tower in N-Space, Cybermen led by Cyber-Leader One used their cyber wrist blasters to kill the two operators of the Ghost Shift, which the Cybermen used to transport the full force of five million Cybermen from the parallel Earth. (TV: Army of Ghosts) Though the Cyber-Leader ordered the surrender of the human race, the Cybermen were engaged by human armed forces such as the British Army in London, leading to the deletion of soldiers at the hands of the Cybermen.
When Dalek Thay, a representative of the Cult of Skaro, denied the Cybermen's proposal for an alliance, Cyber-Units Ten-Six-Five and Ten-Six-Six decreed that "hostile elements will be deleted", proceeding to open fire upon the Dalek. However, it became apparent that their firepower had no effect on the Daleks, and the two Cybermen were immediately exterminated. Soon after, the Cybermen, in a collaboration with the Preachers and using energy blasters modified by the Tenth Doctor, were able to temporarily impair the Daleks' casings, but were still unable to kill them, even when they joined with both the Preachers and Torchwood One's soldiers in a combined assault upon the Cult of Skaro, that became known as the Battle of Canary Wharf. (TV: Doomsday)
Lisa Hallett, who was partially converted at the Torchwood Tower, attempted to delete the Torchwood Cardiff team. Ultimately, she only managed to electrocute Jack Harkness twice; as an immortal, Jack survived both of the successive, otherwise fatal injuries, noting that he was "not so easily deleted." (TV: Cyberwoman)
In 1851, survivors of the Battle of Canary Wharf, having found a human family with infostamps, deleted Caroline Lake. They then pursued and attempted to delete Jackson Lake, who assumed the identity of the Doctor. He was, however, defended by the Tenth Doctor, who asserted his identity to the Doctor before Jackson used an infostamp to destroy them. Jackson later determined that the Cybermen were responsible for the murder of the Reverend Aubrey Fairchild, whose body was found with burns to the forehead in an apparent electrocution. As it turned out, his deletion was executed to gather London workhouse managers, Misters Scoones, Cole, Fetch and Milligan, at his funeral where they could be converted into drones by the Cybermen. All the other men in attendance, including the Vicar, were deleted.
The four men were made to gather orphans to complete the CyberKing dreadnought. They were then terminated by Mercy Hartigan, the Cybermen's human accomplice when they were of no further use. Mercy was intergrated into the CyberKing, using her newfound power to usurp and destroy the Cyber-Lord. When the children's work was done, the Cybermen ordered the deletion, but they were saved by the Doctor, Jackson and Rosita. In a demonstration of the dreadnought's power, Mercy had the CyberKing fire indiscriminantly upon the city of London. Ultimately, however, the CyberKing was destroyed by the Doctor. (TV: The Next Doctor)
In the far future, driven by Ashad's hatred of organic life, the Cybermen abandoned their goal of upgrading humanity in favour of genocide with Ashad's Cyberguards proclaiming that "All humans will be deleted". (TV: Ascension of the Cybermen)