When you lodge documents at DFAT in person or via post you need to complete the Document Service Request and Payment Form. See the link to the form:
https://smartraveller.gov.au/services/legalising-documents/Documents/document-legalisation-request-form.pdf

Some things:

  1. Your Details – does not need explanation
  2. Type of documents – just an identifier, eg Statutory Declaration, Power of Attorney. If you have more than one you can say eg Company documents, or Stat Dec and POA or employment related documents.
  3. Country – most people are clear to where the documents are going.
  4. The DFAT officer can complete this for you. Some countries will be issued an Apostille. A list of these countries can be found at:
    https://www.hcch.net/en/instruments/conventions/status-table/?cid=41
    If the country is not on the list then it will be an Authentication.
  5. If you want DFAT to post it via regular mail they will, for free (domestic or regular Air Mail). If you want the mail to be traceable (highly advisable if it is important documentation) then I would include an express post trackable envelope filled in with your return details. Also, its up to you but I would have DFAT send everything to someone in Australia and then have that person arrange for the postage overseas. That way they can ensure it is traceable courier or mail.
  6. Credit card authorisation details – DO NOT complete if you are attending in person with an appointment. You only need to complete this if you are posting the document to DFAT. Also, please note DFAT ONLY accepts payment by eftpos card. DFAT will not accept CASH or cheque.