This definition appears very rarely
See other meanings of NN
We have 17 other definitions for NN
in our Acronym Attic
Samples in periodicals archive:
In this latter case, he responded to his distaste of the process by simply refusing to apply the epoxy, such as in the piece Nomen Nescio 135.
Nomen Nescio is a title Reijnders often gives to his works.
standing either for first and last name, or for nomen nescio, "the name, I do not know" (1)).