A reduced PID tag set specification represents POS transaction data in a manner that is largely retail store product specification independent. A reduced PID tag set specification is a tagged format specification in which a number of PID tags in the tagged format specification is less than the number of PIDs for products contained in RS POS CSs PID specification. In a preferred embodiment, there is only one tag set defined for identifying product identification datum as such. As a result, the product descriptions of all of the product identifications that exist in a retailer's product identification specification are lost when saving the same data in the preferred reduced PID tag set specification. However, saving the retailer's transaction data in a reduced PID tag set specification moots the need to know the retailer's product identification specification in order to receive, store, organize, and, to a certain extent, process the retailer's transaction data.