For items array, all the parameters are required except for the following:
<Parameters that are low-priority and optional for items array>
- externalVendorSku: item code used by the seller/vendor
- barcode
- emptyBarcode: no barcode available
- emptyBarcodeReason: reason why no barcode is available
- modelNo: model number
- extraProperties: additional option info about the seller's item
- certifications: any certification about the item
- searchTags: search words