GS1 Specification
Some brief information on the GS1 specification including the topics of applications, barcode types and check digits can be found here

GS1

Barcodes according to GS1 are used in a wide variety of industrial sectors. In retail and food, in transport, logistics and healthcare. A UDI-compliant marking is possible with the system. Use the pixel based scan method if you want to check the leading FNC1 character as well. The new barcode detection method automatically fills in a missing FNC1 character. In most cases, code 128 and data matrix barcodes are used.

Validation

When evaluating according to GS1, all results are displayed with barcode information and evaluated identifier. The product identifier (the GTIN for GS1), the time stamp of the scan, the scanner ID as device identifier and the barcode type are displayed there. The overall result of the evaluation and the barcode content are below.

result-01-en

Then follows a list of evaluated identifiers. For the GS1, the Application Identifier is displayed (like 01 for the GTIN), the English short name, the translated name and the content. For some identifiers like the date, a formatted data display is used for the content. Tapping on the identifier displays the details about it.

result-02-en