How the Default Grouping field in Auto Create group data

Hi,

From below message how is the default Option grouping data they grouping by same item or revision or line type or grouping  by same item and same revision and same line type?

Because I create two PR lines in difference Line type but same Item same revision same need-by-date but when auto create by choose groupping option to default they group my item into single line.

Select the Grouping for requisition lines on the document:

•   Default: Combine requisition lines for the same item, revision, line type, unit of measure, supplier item number, and transaction reason onto one purchase order line. Combine requisition lines for the same item, revision, supplier item number, and line type onto one RFQ line.