Invoice posted through EDI without parking

Hi,

from x to y, normally we receive Invoices as EDI data after we create PO and send data through EDI.

Those invoice data are parked in y and we verify and post the IV data from the TC MIR6.

But for some invoice data we found that they have been posted automatically by RFCUSER without our operation.

This automatic posting should not happen as those must be posted by our end.

I have checked the customized setting OBCE but nothing like automatic posting is set..

why they have been posted based on what kind of setting without parking?

Regards

vr