In the early decades of the twentieth century, in the Dutch East Indies, the study of adat emerged as a specialised field of inquiry. Although associated with the needs of colonial administration, this study nevertheless gave rise to an active scholarly discipline that dealt with differing systems of adat comparatively. Among notable scholars in this study were, Van Vollenhoven, Ter Haar and Snouck Hurgronje. Several key concepts that are still being used today within the customary law research in modern Indonesia are; "adatrecht" ('adat law'), "adatrechtskringen" ('adat law circles'), "beschikkingsrecht" (communal rights over land or 'right to avail') and "adatrechtsgemeenschappen" ('adat law communities'). The adat law or adatrecht has been used by colonial government as a legal term designating a prescriptive right, which was given currency as an independent legal entity apart from the canon law. Local indigenous laws and customs of all ethnic groups, including those of non-Muslims, began to be collectively termed as "adat", and were encoded into units of jural management, whereby legal pluralism in East Indies was introduced. Under this scheme, based on a classification of adat systems as cultural geographic units, the Dutch divided the East Indies into at least 19 adat law areas.