All updated guidance can be found here, including a PDF download of questions and guidance on how to use the X sub-codes from your own attendance data to help complete the daily return:
How to complete the educational setting status form - GOV.UK (www.gov.uk)
If you need any help with regards to getting the information to the DfE, or if you have queries around the questions you are being asked:
You can email firstname.lastname@example.org if you have any questions about completing the form.
You can also use the DfE coronavirus helpline if you have a query about the form or for general queries about coronavirus (COVID-19). If you have a unique reference number or UKPRN, please have it available when you call.
The helpline can also help with setting up an IDAMS account.
DfE coronavirus helpline
Telephone: 0800 046 8687