Slavic microlanguages are literary and linguistic forms that exist alongside the better-known Slavic languages of historically prominent nations. The term "literary microlanguages" was coined by Aleksandr Dulichenko at the end of the 1970s and subsequently became a standard term in Slavistics.
Slavic microlanguages exist both as geographically and socially peripheral dialects of more well-established Slavic languages and as completely isolated speech forms. They often enjoy a written form, a certain degree of standardization and are used in a variety of circumstances typical of literary languages, albeit in a limited fashion and always alongside a national literary language.
Read more about Slavic Microlanguages: Insular and Peripheral Microlanguages, Functional Characteristics