• Non-profit organization
  Non-profit organization
  Nonprofit organization is neither a legal nor technical definition but generally refers to an organization that uses surplus revenues to achieve its goals, rather than distributing them as profit or dividends...
  
  
• Nil per os
  Nil per os
  Nil per os is a medical instruction meaning to withhold oral food and fluids from a patient for various reasons. It is a Latin phrase which translates as "nothing through the mouth". In the United Kingdom it is translated as nil by mouth .Typical reasons for NPO instructions are the prevention...
  
  , Latin for "nothing by mouth", a medical instruction to withhold oral intake of food and fluids from a patient
• NP optimization problem, optimization problems that are NP-hard
• North Pacific Oscillation
  North Pacific Oscillation
  The North Pacific Oscillation is a teleconnection pattern first described by Walker and Bliss and characterized by a north-south seesaw in sea level pressure over the North Pacific.Rogers, using surface atmospheric temperature from St...
  
  , an atmospheric teleconnection pattern

Britain

• National Preservation Office
  National Preservation Office
  The National Preservation Office was established by the British Library Board in 1984. In 2009 it was renamed the British Library Preservation Advisory Centre...
  
  , part of the British Library
• NPO UK Ltd., a company which had stationery and book shops around Northern Ireland, bought by and rebranded Eason & Son
  Eason & Son
  Eason & Son is a group involved in the wholesale, distribution and retail of books, newspapers, magazines, stationery and cards on the island of Ireland ....
  
   N.I. Ltd.

Netherlands

• Netherlands Public Broadcasting 
• Netherlands Pathfinder Organisation , one of the organisations that evolved into Scouting Nederland
  Scouting Nederland
  Scouting Nederland is the national Scout organisation of the Netherlands with approximately 110,000 members Scouting Nederland is the national Scout organisation of the Netherlands with approximately 110,000 members Scouting Nederland is the national Scout organisation of the Netherlands with...
  
  , the national Scouting organisation of the Netherlands

Russia

• Nauchno-Proizvodstvennoye Obyedineniye (Научно-производственное объединение), Russian for "Scientific and Production Establishment", often found in the names of successors to the Experimental Design Bureaux (OKB
  OKB
  OKB is a transliteration of the Russian acronym for "Опытное конструкторское бюро" - Opytnoe Konstructorskoe Byuro, meaning Experimental Design Bureau...
  
  ) of Communist times