Registration requirement for excisable goods obliges producers, traders and eligible importers unless exempted by Board notification. Registration is required for persons producing, manufacturing, trading, holding storerooms or otherwise using excisable goods, and for importers issuing invoices eligible for CENVAT credit; registrations under certain earlier rules are deemed valid. The Board may, by notification and subject to conditions or limitations, exempt persons or classes from registration and may specify the conditions, safeguards and procedure for registration.