Aadhaar authentication requirement affects GST registration eligibility and validity, with alternatives and registration consequences for taxpayers. The Act recognises the National Appellate Authority for Advance Ruling as the national forum for conflicting advance rulings, prescribes appeal procedures and binding effect of its rulings; creates a capped composition-like option for certain small registered persons with specified disqualifications and related turnover computation rules; mandates Aadhaar-based authentication or alternate identification for registration and authorises electronic payment mode requirements; permits transfers among electronic cash ledgers and corresponding State-Central account transfers, modifies return periodicity and payment timelines, and adds a profiteering penalty for failure to pass on tax or input credit benefits.