Curiosity Question - API Response to Erp.BO.SalesOrderSvc/GetNewOrderHed

Why would the response body for ‘OrderHed’ have two entries when starting an order. The only differences I note are the first contains the information I’m populating for the order and the second’s PlantName has the technical name of our second site and a row mod = ‘A’

{
“parameters”: {
“ds”: {
“OrderHed”: [
{
“Company”: “rrrr”,
“OrderNum”: 0,
“CustNum”: 1,
“ShipToNum”: “abc”,
.
.
“PlantName”: “”,
.
.
“TaxRegionCodeDescription”: “”,
“TermsCodeDescription”: “”,
“RowMod”: “”
},
{
“Company”: “rrrr”,
“OrderNum”: 0,
“CustNum”: 0,
“ShipToNum”: “”,
.
.
“PlantName”: “second site”,
.
.
“TaxRegionCodeDescription”: “”,
“TermsCodeDescription”: “”,
“RowMod”: “A”
}
],
“OrderHedAttch”: [],

Sometimes it does that. Pretty sure Update() will ignore the first row since it has no RowMod.