NTIN presented as EAN13, is presently the dominant product code in use in Norway. The NTIN is constructed from the Vnr and consequently a non-changeable unit. GTIN comply with the same 13 digit format as NTIN, EAN13. The GS1_Healthcare_GTIN_Allocation_Rules_16092016 is available at http://wiki.vnr.fi/
A separate document on implementation of 2D Data Matrix in Norway is available at Farmaloggs website. This contains information on change from NTIN to GTIN and from barcode to 2D Data Matrix. This subject is more fully covered at http://wiki.vnr.fi/ .