Males use a consonant, females use a vowel. Only one person is not referred to by a letter and number, the overall leader of the One State. He is an elderly man known as the Benefactor. During the novel he is re-elected for the 47th time during a great annual holiday called the Day of Unanimity. D-503 is puzzled by the fact that among the 'ancients' the results of elections were unknown before voting took place.
All numbers dress alike in an identical pale blue 'unif', a gender-neutral outfit.
Heads are shaven, adding to the monotonously look-alike appearance of male and female inhabitants. New unifs are distributed to all numbers as part of the annual ceremonies of Unanimity Day. The One State is surrounded by a Green Wall. It is implied that the One State is the only urban area left from this conflict. A total of only 0.2 of the earth's population at that time survived the conflict.