nomenclator

noun4

1. •
   One who assigns or constructs names for persons or objects or classes thereof, as in a scientific classification system.

   • The nomenclator's method is first to look about and see if the place has any natural features to suggest a name—like Rocking Stone Farm or White Birches. — 1969
2. •
   An assistant who specializes in providing timely and spatially relevant reminders of the names of persons and other socially important information.

   • If he does not know them, it is deception to pretend that he does, while all the time he has never heard of them until instructed by the nomenclator. — 1956
3. •
   An early form of substitution cipher.
4. •
   A document containing such name assignments.