definiens: means ( i ) the Conversion Stock ; ( ii ) shares of the Company 's Common Stock issuable or issued upon conversion of the Company 's Series C Preferred, Stock ; ( iii ) shares of the Company 's Common Stock issuable or issued upon conversion of the Company 's Series B Preferred Stock ; ( iv ) exclusively for purpcses of registrations pursuant to Section 9.5 hereof, up to 43,193 shares of Common Stock issuable to Arthur R. Engel ( ) ; and ( v ) any shares of Common Stock of the Company issued or issuable, directly or indirectly, in respect of the Conversion Stock, Series C Preferred Stock, Series B Preferred Stock or such stock issued to Engel, upon any stock split, stock dividend, recapitalization, or similar event, or any shares of Common Stock otherwise issued or issuable with respect to such stock ; provided, however, that Registrable Securities shall not include any shares of Common Stock which have previously been registered or sold to the public, or any Registrable Securities sold by a person in a transaction in which his rights under this Section 9 are not assigned