Providing services to unlisted companies must be segregated into a separate business unit with a mandatory disclaimer and transition period. Regulation 12 requires registrars to operate services to unlisted companies through a separate business unit, treat those services as outside the Board's regulatory jurisdiction, and provide an appropriate disclaimer to unlisted companies; registrars serving mutual funds and similar investment entities remain under the Board's purview, and existing providers must segregate such activities into a separate business unit within eighteen months of notification.