Successful identification of products in the global supply chains is an integration of two pieces. The second piece is the defined data carriers of the data structures. The data carriers are the supported bar coding symbologies. Any company could define many different data structures and choose to encode them in any number of publicly available symbologies. The company has therefore defined its own internal standard.
Internal standards can be very beneficial, but only internal to the company.
Outside receivers of the product have no way of knowing what data is contained in the bar codes assuming they happen to support the symbology the data is encoded in. Certainly the receiver could implement the other company s internal standard. But imagine if every company they received from had their own incompatible internal standard. The receiving company would be unable to support all these disparate standards. It would be chaos.