R12.1.3 - Projects related data in the AP_INVOICE_LINES_ALL table

I know this is an AP question but it concerns the projects related data in the new AP_INVOICE_LINES_ALL table so I think the chances of getting an answer from this group may be higher than from AP.

Is there a write-up or white paper that explains the use of the project related data in the ap_invoice_lines_all table?  I think I understand why they put the data in the lines table as it is analogous to the pa_expenditure_items_all table and this is where that data is in PA.

 

I also verified that the interface suppliers invoices program still uses the PA data in the distributions table.