an information - transmitting apparatus for transmitting data records , each comprised of a plurality of data words , each word comprising a plurality of digits , wherein data words of a data record are compared with the next successive record which is also comprised of a plurality of data words . each data word of a first record is compared on a digit - by - digit basis with the corresponding data word of a second record , and various digits of the data words of the second record which are identical with those of the corresponding data words of the first record are omitted . deletion of identical digits of a data word of a second record is continued until a non - coincidence detection signal is produced . then , the remainder of the digits of the data word of the second record are transmitted . additionally , special codes which separate the data words and which separate the records are also transmitted .