The document discusses the GST reverse charge mechanism (RCM), where the tax liability shifts from the supplier to the recipient in certain cases, such as supplies from unregistered to registered dealers and services via e-commerce operators. Key features include an expanded scope, compulsory registration for liable parties, and the inability to use input tax credit for payments under RCM. Additionally, it outlines provisions under the CGST Act, specifying notified goods and services subject to reverse charge and establishing payment requirements.