Hello. I'm trying to add a Multiple Select field for Item Class in Suitelet but it does not working. Could someone tell me what is the source please?

var itemClass = form.addField({
                    id: 'custpage_item_class',
                    label: 'Item Class',
                    type: serverWidget.FieldType.MULTISELECT,
                    source: 'class'
                });

I tried this but it shows empty. I changed class to department and it works but not the class

https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/section_4273205732.html#bridgehead_4273217274

record.Type.CLASSIFICATION

Thank you @ec That works