Pre-filing of draft offer document permits limited retention of convertible securities subject to mandatory conversion before regulatory observations. Pre-filing of a draft offer document allows continuation of certain outstanding convertible securities and rights during the Board's review, provided outstanding convertible instruments are mandatorily converted and intimated to the Board before observations; specified employee stock options and fully exercised stock appreciation rights with disclosure may remain after observations. Fully paid-up convertibles must be converted by filing of the red herring prospectus or prospectus, and mandatorily convertible securities must be detailed in the updated draft red herring prospectus-I. Material changes linked to listed matters require updated or fresh filings with prescribed fees, while certain pre-observation changes need not be refiled.