⢠I've tried a client script with both the validateDelete and sublistChange entry points, and a beforeSubmit user event script.
⢠That's a good suggestion about the contact record, though I don't think the company field is the source for customer/contact relationships - company can be null, with the relationship still showing in the sublist.
⢠I believe what's happening is that clicking attach/remove creates/deletes a join between the two records, but NetSuite doesn't provide access to the join table.