sentences:  However, purchases from certain related parties are effectively ignored and the inventory may be considered produced by the taxpayer.Various other systems have rules for determining what portion of income from inventory produced domestically and sold foreign or vice versa is sourced foreign.Where a system limits the credit based on domestic tax generated by foreign source net income, it must provide a mechanism for determining net income subject to home country tax, including associating deductions or exclusions with income for such purpose.