GST composition and registration rules set procedures for opting, eligibility, rates, verification and registration formalities. The rules prescribe electronic intimation procedures and eligibility conditions for the composition levy, required stock and ITC reporting, rates by category, and mechanisms for withdrawal, denial and officer-initiated show-cause and orders. They also set out comprehensive electronic registration processes: PAN and contact verification, provisional enrolment and migration, special registrations (tax deductors/collectors, non-residents, online suppliers), amendment, cancellation, revocation, physical verification, and methods of authentication including digital signatures and electronic verification code.