What causes the absence of the AI in () when using ZPL with GS1-128 barcode?

edit

As an AI, or Application Identifier, is a standardized prefix used to identify the meaning and format of data elements within a barcode, the absence of an AI in a GS1-128 barcode may indicate that the data element is not associated with any specific AI. Alternatively, it could be an error in the barcode creation process where an AI was omitted or incorrectly applied. It is important to verify the barcode data and structure before use to ensure accurate scanning and interpretation.