Is there a lacuna in AOC4

I have to file an AOC4 for a company with unaudited, un-adopted and provisional accounts.
But the Form AOC4 in point no 6 asks for the date when auditor has signed the accounts which is yet not available with us. This field is mandatory !
How do I complete the form as stated above and submit the provisional, un-adopted and unaudited accounts with this mandatory field the information on which is currently not available with us.