'Processed metals`, referred to in paragraphs 5 and 6, means the metals in the most basic form in which they are customarily traded on international terminal markets. For this purpose, the Authority shall specify, in its financial rules, regulations and procedures, the relevant international terminal market. For the metals which are not traded on such markets, 'processed metals` means the metals in the most basic form in which they are customarily traded in representative arm's length transactions.