Particularly vulnerable tribal group
A particularly vulnerable tribal group or PVTG (previously known as a primitive tribal group), in the context of India, is a sub-classification of Scheduled Tribe or section of a Scheduled Tribe, that is considered more vulnerable than a regular Scheduled Tribe. The PVTG list was created by the Indian Government with the purpose of better improving the living standards of endangered tribal groups based on priority.
Source: Wikipedia — Particularly vulnerable tribal group (CC BY-SA 4.0)