Nomen nescio, abbreviated to N.N., is used to signify an anonymous

Anonymity

Anonymity is derived from the Greek word ἀνωνυμία, anonymia, meaning "without a name" or "namelessness". In colloquial use, anonymity typically refers to the state of an individual's personal identity, or personally identifiable information, being publicly unknown.There are many reasons why a...

 or non-specific person. From Latin nomen, name, and nescire, not to know, be ignorant of. Together, I do not know the name.

One use for this name is to protect against retaliation when reporting a crime

Crime

Crime is the breach of rules or laws for which some governing authority can ultimately prescribe a conviction...

 or company fraud

Fraud

In criminal law, a fraud is an intentional deception made for personal gain or to damage another individual; the related adjective is fraudulent. The specific legal definition varies by legal jurisdiction. Fraud is a crime, and also a civil law violation...

. In the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 a police suspect that refuses to give his name is given an "N.N. number." In Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, and Belgium

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, N.N. is also frequently seen in university

University

A university is an institution of higher education and research, which grants academic degrees in a variety of subjects. A university is an organisation that provides both undergraduate education and postgraduate education...

 course lists, indicating that a course will take place but that the lecturer is not yet known; the abbreviation is sometimes explained as "nomen nominandum" ("the name is to be announced") in this case.

N. N. is commonly used in the scoring of chess games, not only when one participant's name is genuinely unknown but when an untitled player faces a master, as in a simultaneous exhibition

Simultaneous exhibition

A simultaneous exhibition or simultaneous display is a board game exhibition in which one player plays multiple games at a time with a number of other players. Such an exhibition is often referred to simply as a "simul".In a regular simul, no chess clocks are used...

. Another reason is to protect a known player from the insult of a painful defeat.

The generic name Numerius Negidius

Numerius Negidius

Numerius Negidius is a name used in jurisprudence in ancient Rome based on a play on words: Numerius Negidius means "one who denies that he should pay ", and was used specifically to refer to the defendant in a hypothetical lawsuit....

 used in Roman

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 times was chosen partly because it shared initials with this phrase.

Genealogists

Genealogy

Genealogy is the study of families and the tracing of their lineages and history. Genealogists use oral traditions, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of its members...

 often use the abbreviation to signify an unknown or partially unknown name (such as N.N. Jones).

See also

• John Doe
  John Doe
  The name "John Doe" is used as a placeholder name in a legal action, case or discussion for a male party, whose true identity is unknown or must be withheld for legal reasons. The name is also used to refer to a male corpse or hospital patient whose identity is unknown...
  
  
• Nescio
  Nescio
  "Nescio", Latin for "I don't know", was the pseudonym of the Dutch writer Jan Hendrik Frederik Grönloh, born June 22, 1882 in Amsterdam and died July 25, 1961 in Hilversum, both in the Netherlands. Grönloh was a businessman by profession; as Nescio he is mainly remembered for the three novellas De...
  
  
• Mister X
  Mister X
  Mister X or Mr. X is commonly used as a pseudonym for someone whose name is secret or unknown.Mister X may refer to:- Comics :* Mister X , a character from the intercompany crossover...
  
  
• To be announced
  To be announced
  To be announced, To be confirmed, and To be determined are placeholder terms used very broadly to indicate that although something is scheduled or anticipated to happen, a particular aspect of that thing remains to be arranged...