In Yevgeny Zamyatin's dystopian novel We, the protagonist's official designation is D-503.
D-503 is a mathematician and spacecraft engineer living in the One State. He is the builder of the Integral, a vessel intended to carry the One State’s ideology to other worlds. At the beginning, he embraces the regime’s strict rationality, collective schedules, and numbered population.
His encounters with the rebellious I-330 disrupt his confidence in a society organized around mathematical certainty. As he writes his record, he develops imagination and emotional conflict, qualities the One State treats as dangerous illnesses. The use of alphanumeric designations reflects the regime’s attempt to replace individual identity with administrative order.
Zamyatin wrote We in the early 1920s, and it was not legally published in the Soviet Union during his lifetime. An English translation appeared in 1924. The novel strongly influenced later dystopian fiction, including Aldous Huxley’s Brave New World and George Orwell’s Nineteen Eighty-Four.