Homogeneous and heterogeneous diglossia.

Even if diglossia is total and universal, we must determine whether the L norm is in fact one variety or more than one, i.e. is it homogeneous or heterogeneous. That is, is there an L variety that can be used for communication throughout the linguistic culture and with all segments of the speech community, such that no one is forced to resort to the H variety (written formal/spoken) or some other language, as a lingua franca. In Switzerland, no one L-variety is recognized as standard; speakers must learn to accommodate their variety to those of others, since the use of H Schriftdeutsch is not considered appropriate between Swiss citizens (Schiffman 1991).