20. The method of claim 19 , wherein said body portion comprises (a) said domain designator, (b) a number having a string length of (Y−2) characters, and (c) a single check digit calculated according to said checksum validation routine, wherein said domain designator comprises a single digit between zero and nine.
21. The method of claim 20 , wherein said body portion is generated such that said tokenized data string passes said checksum validation routine.