For instance, a noun ending in the -nak/-nek suffix may be in the genitive or in the dative case, thus the MSD codes Nc-sd (a singular noun in the dative) and Nc-sg (a singular noun in the genitive) will be reduced in a different way.
the codes Nc-sd and Nc-sd---s3 will be reduced to the same form since there is no such Hungarian lemma that would have the same word form for a dative singular and a dative singular with a third person singular possessor (and thus, the POS-tagger would not have to choose between these possibilities).