new format of form 16 & 16A

hi, i m working as an account executive in a medium based co. after issuing a tds certificate i came to knw that theere is a new format of form 16 & 16 A in which u have to mention acknowledgement receipt no of quarterly retun. i ssued a tds certificate in old format in which i did not mention acknowledgemt receipt no. can anybody tells that wat a law say in this case. is any penalty arise in this case