Deutsche Gebärdensprache
ÖGS and Hungarian Sign Language seem to be related for historical reasons (First School for the Deaf in Vienna), but forms a cluster with neighboring languages rather than with ÖGS. Although there are no detailed studies of the extent of relatedness, ÖGS shares aspects of its grammar with German Sign Language and Swiss Sign Language, while the vocabulary differs (see Skant et al. 2002); Wittmann (1991) places it in the French Sign Language family).