Taxable Flag and Tax Classification Code in R12

Prior to R12 upgrade, the taxable and tax_code_id information was stored in po_line_locations_all, but now it is stored elsewhere.  We want to re-point our reports to the new data location.  We can create & update POs, adding or updating the tax classifcation on the "Additional Tax Information" sub-sub form. (from inside PO, click tools > manage tax.  On the pop-up form click additional tax information.  The data is displayed on the next form, at the bottom right).

Does anyone know where the data is stored?  Also, has the lookup of the tax_code_id moved or is it still using AP_TAX_CODES_ALL?