Vendor Master: IS-OIL Additional Data - screen layout

Hello,

I've a SAP ECC 6.07 system with activated IS-Oil functionality. In the vendor master, we have a specific tab called "IS-Oil Additional data - General" with some specific fields.

My question is where can I modify the screen layout (hide, make mandatory etc. any of the fields) of this tab? It can't be found within the standard customizing path under Financial Accounting (new).

Thanks and Best Regards,
Tamás