Hello and welcome to the customer community. In general, in VIP, once you create and link your items, you list the item. From there you will complete the process we call "topping off" where you provide values for the recipient-specific attributes, including the class attributes in VIP.
We have some information for you in the community to help with some of these concepts. Please let me know if these areas help as well:
https://community.1worldsync.com/t5/Knowledge-Articles/Kroger-Quick-Sheets-for-Non-GDSN-VIP/ta-p/108...
https://community.1worldsync.com/t5/Knowledge-Articles/tkb-p/Documentation
