A valid Discount group should not contain characters like double apostrophes (“) and hyphens (-). And, it should be less than 30 characters. Also, we don’t recommend using special characters in your Discount group tag.
Note: Customer tags in the Discount group are NOT case-sensitive.
You can add a tag according to the discount you want the customer to access. For example, ‘wholesale’, ‘wpd50’, 'STUDENTdiscount', 'bcfmDISCOUNT' etc.
You can learn more about customer tags here.
Here's an example of tags associated with the Discount groups shown in the image below: