Proper noun
N.N.
Used as a substitute for an unknown name or one that the writer wishes not to reveal.
American Journal of Physics vol. 77, pages 526 537 Examples include a solid body with a cavity filled with an inviscid, incompressible, homogeneous liquid, N.N. Moiseyev and V.V. Rumyantsev (1968). Source: Internet
S.) N.N., Regele României; both forms are accepted by the Romanian Academy ) The English translation is: His Majesty (H. Source: Internet
The papers have been reviewed by a large number of academics including Dr. Travis Perera, Dr. N.N. J. Nawarathne and Prof. Prasadini Gamage. Source: Internet