Anyone have knowledge about the over/undership fields in OrderDtl?

We routinely have arrangements with our customers where they will accept a certain level of under and/or overshipment against the order because of production lot sizing and unknown level of scrapping which will ultimately result from production. There are std Epicor fields on OrderDtl which seem to point to “handling” this situation (UndersPct, Unders, Overs, OversUnitPrice) but there is nothing in the on-line help about these fields. Also, they are only exposed in Summary > Lines Detail and Lines > List. They are not found on the Lines > Detail UI (but could be exposed with custom code). I’ve run a SOA and a Pro-forma using std Epicor and it doesn’t kick out anything seemingly related to values in these fields. I can easily add some custom code which triggers on data in those fields. My question is if anyone out there has had any dealings or knowledge about these fields???