Preservation of company registers required; member register permanent, other security registers and annual returns retained for statutory periods. Rule 15 requires preservation and custody of company registers and annual returns: the register of members and index must be preserved permanently in the custody of the company secretary or a Board-authorised person; registers of debenture holders or other security holders and copies of annual returns with annexures must be preserved for a statutory limited period from redemption or filing and similarly kept in custody; foreign registers follow parallel rules with permanent preservation for member registers unless transferred and statutory retention for security registers.