1. A method for a client computer to retrieve a computer file comprising the steps of: a) encoding a symbol data string comprising a file location pointer into a machine readable symbol; b) rendering said machine readable symbol within a data carrier; c) transposing an input data string from said machine readable symbol with a computer input device coupled to said client computer; d) parsing said input data string to determine said file location pointer; and e) utilizing said file location pointer to request the computer file designated thereby, by assembling a computer file transfer request word comprising said file location pointer, and transmitting said computer file transfer request word to a target server computer via a computer network system; f) said target server computer receiving said computer file transfer request word and g) said target server computer transmitting a computer file to said client computer in response thereto; wherein said machine readable symbol also has encoded therein a source identifier data string, said source identifier data string comprising data correlated to an expected user of said data carrier, and wherein said source identifier data string is transposed by said computer input device.