Guidelines to create GS1 DataMatrix labels
When you generate the GS1 DataMatrix using our Barcode Generator SDK, you have the option to add values with or without the brackets. The SDK will automatically add the brackets where they're needed. You can also include the "|" separator such as the one used in GS1 Australian Post.
Here's a GS1 DataMatrix generator sample code https://docs.bytescout.com/barcode-sdk-c-gs1-datamatrix-barcode