This step can also be completed during the initial bidder registration process. If UNSPSC codes were selected during that process, those codes would already be reflected here in the UNSPSC Classification list.
However, more codes can be added by clicking the UNSPSC Classification Look Up. Similarly to the Service Areas section, you can select as many UNSPSC codes as needed by searching for a new code, and then adding it to the list below.
The list will show all UNSPSC codes that you have chosen.