This description of  the structure of  Old Church Slavonic is intended to present fully the important data about the language, without citing all the minutiae of attested variant spellings. The facts have been treated from the point of view of structural linguistics, but pedagogical  clarity has taken precedence over the conciseness required for elegant formal description. Old Church Slavonic was used over a period of some two hundred years and in various geographical parts of the Slavic world.