table for blanket purchase agreements

Standard PO's have a record in the po_line_locations_table but unless there is a release the blanket purchase agreements don't seem to have a record in this table but yet when viewing the form Purchase Orders under the price breaks table we see information--where does it pull that information?

I understand a line should exist in po_line_locations_all table with

SHIPMENT_TYPE = 'PRICE BREAK'

but these lines do not have this and yet I can see it on the price break table