The roots of the current orthography for Northern Sami were laid by Rasmus Rask who, after discussions with Nils Vibe Stockfleth, published "Ræsonneret lappisk sproglære efter den sprogart, som bruges af fjældlapperne i Porsangerfjorden i Finmarken. En omarbejdelse af Prof. Knud Leems Lappiske grammatica" in 1832. Rask opted for a phonemic orthographic system. All of the orthographies that have been used for Northern Sami trace their roots back to Rask's system, unlike the orthographies used for Lule and Southern Sami, which are mainly based on the orthographical conventions of Swedish and Norwegian. Following in the tradition of Rask meant that diacritics were used with some consonants (č, đ, ŋ, š, ŧ and ž), which caused data-processing problems before Unicode was introduced. Both Stockfleth and J. A. Friis went on to publish grammar books and dictionaries for Sami. It can be said that Northern Sami was better described than Norwegian was before Ivar Aasen published his grammar on Norwegian.