The word 登记 is formed by combining two meaningful characters: 登, which originally depicted a ritual ascending of steps and conveys the idea of formally stepping into or entering something, and 记, which signifies the act of recording or writing down. Together, they create a compound where the first character provides the context of a formal, upward or entered action, and the second character specifies the nature of that action as one of recording, resulting in the unified meaning "to register" or "to formally record".