Impression is the process by which a person becomes a Dragonrider. During Impression, a telepathic bond is formed between a newly-hatched Dragon and a boy or girl, generally a teenager. Once Impression is made it is unbreakable. The psychic bond is so strong that a Dragon cannot live without its rider and will go between to die if its rider dies. If a Rider's dragon dies, the Rider cannot Impress a new hatchling, and the Riderless, as they are known, generally leave the Weyr. Many suicide rather than face life without their Dragon.
At the moment of Impression, the Dragon tells his or her rider their name. Male riders contract their name to show their new status. For example, Felar became F'lar. This custom appears to have been formalized under Weyrwoman Torene of Benden Weyr during the First Pass.