population statistics.42 In addition, any person who is born in Norway, as well as others who have been granted a Personal Identification Number (fødselsnummer), such as children born outside Norway to a Norwegian parent, are registered in the CPR. Those who have been granted what is known as a D-number are also registered in the CPR.43 SSB uses extracts from the CPR to produce and publish demographic statistics, but it is also able to produce statistics based on other data if it is of relevance to the descriptive and analytical use of statistics from SSB.44 Based on the information received from CPR, SSB creates its own version.45 SSB has also carried out research commissioned by UDI aimed at estimating the number of persons living in Norway without legal residence.46 The National Police Immigration Service (NPIS) has provided insight into internal registration, working methods, and data quality for this study.47 NPIS registers statelessness on the basis of the information given by the applicant upon his or her application, such as an asylum application that is submitted to the NPIS.48 As for publishing, it only publishes statistics on forced return.49 Improvements have been made in recent years to harmonize the working methods for registration by these authorities.50 However, the CPR and UDI register different “populations,” which means they cannot produce the same statistics. It is thus stated below when the relevant statistics are drawn from NR or UDI. The CPR receives information from various sources, as different registration systems are connected with the CPR, such as the Alien Register and tax offices. As statelessness in Norway often occurs in a migratory context, the Alien Register (Utlendingsdatabasen or “UDB,” updated through Datasystem for utlendingsog flyktningsaker, DUF) is of a great importance. UDI, NPIS, and the Immigration Appeals Board all use the UDB for information and registrations about applications from foreign citizens for visitors’ visas, residence permits, international protection, and citizenship, as well as the handling of expulsion cases, the return of persons without a legal right to be present in Norway, and appeals.51 The UDB covers stateless persons and has a special code for them. The information in the UDB is transferred to the CPR.52 UDI reports that the definition of a “stateless person” used by the police for the registration of stateless asylum-seekers is the 1954 Convention Article 1(1) definition.53 UDI also uses this definition when assessing the nationality of asylum-seekers. The definition is used by the police and UDI for purposes of registration and establishing an individual’s identity.54 Within the different registration authorities, only limited published rules or guidelines could be found concerning the evaluation of statelessness when the nationality of an 42 See “Dette er folkeregisteret”, available at: http://www.skatteetaten.no/no/Person/Folkeregister/Dette-er-folkeregisteret/. 43 The D-number is a temporary social security number given to immigrants who are obliged to pay taxes in Norway or who seek medical treatment, but who have not been granted legal residence in Norway or who will be residents in Norway for less than six months. Informationavailable at: http://goo.gl/Vpc76q. For more information on the six-month rule, see NR’s guidelines in Skattedirektoratet – Rettsavdelingen, Håndbok i folkeregistering (2011), p. 31. 44 Kåre Vassenden: Bosteds- og bosattbegrepet, SSB 2011, pp. 1-2. 45 Statistisk sentralbyrå, available at: http://www.ssb.no/innvbef_en/about.html. 46 Zhang, LC., Developing methods for determining the number of unauthorized foreigners in Norway. Statistisk sentralbyrå 2008. 47 Kåre Vassenden, Rapport fra en gransking og sammenligning av UDI- og SSB-filer med overganger to norsk statsborgerskap i 2007, 3. utgave, 2009. 48 Interview with the department of strategy and analysis within the NPIS, 21 August 2012. 49 See https://www.politi.no/politiets_utlendingsenhet/statistikk/. 50 Interview with SSB, 20 August 2012. 51 These authorities are also the main immigration authorities in Norway and thus bear responsibility to provide the CPR with information on visas, permits and asylum granted to migrants and refugees, Vebjørn Aalandslid and Lars Østby, Country Report Norway, National Data Collection Systems and Practices, Prominstat 2009, p. 7. 52 SSB, New developments in the relations between the immigration authorities and Statistics Norway, Joint ECE-Eurostat work session on Migration Statistics, Geneva 8-10 May 2000, p. 2. 53 Article 1(1) provides: “For purposes of this Convention, the term ‘stateless person’ means a person who is not considered as a national by any State under the operation of its law.” 54 Letter from UDI of 8 June 2015. UNHCR STOCKHOLM, OCTOBER 2015 17