Most Australia Post tracking number format is a combination of 13 alphabetic and numeric characters, usually starting with 2 alphabets, following by 10 digits and ending by AU e.g. XT 123 456 789 AU.
Consignment is a combination of letters and numbers that represents the group of parcels that are being sent to one recipient or address, this could be one or multiple parcels.
On the other hand an Article is the unique code that will allow you to see details of 1 item.
https://drive.google.com/file/d/1H5UZAJkYHt0M1kIgrl1Bi1ROgbfzsqrA/view?usp=sharing