A document is conditionally exempt if its disclosure under this Act would disclose matter ( deliberative matter ) in the nature of, or relating to, opinion, advice or recommendation obtained, prepared or recorded, or consultation or deliberation that has taken place, in the course of, or for the purposes of, the deliberative processes involved in the functions of:
(a) an agency; or
(b) a Minister; or
(c) the Government of the Commonwealth; or
(d) the Government of Norfolk Island.
(2) Deliberative matter does not include either of the following:
(a) operational information (see section 8A);
(b) purely factual material.
This refers to internal discussions, drafts etc. of reports which were ultimately for publication etc. It has also been used to support a general exemption for peer review documents (i.e. confidential reviews, responses to reviewers etc.).
The request in this case, from Warwick Hughes, asked for peer review materials relating to a review by an Australian agency (BoM) of work by a New Zealand agency (NIWA) (see here for more details on the work in question). This clearly raises issues of international relations (another common theme in FOI legislation), and indeed, BoM make the case that release of a confidential peer review process with an international agency would damage relations between them.
Finally, in refusing Hughes request in the most part, BoM provided a listing of all responsive documents, and whether they would or would not be released. In the US, this is termed a Vaughn index and is frequently requested in cases where requested documentation has not been released. In itself, it often provides additional information (on the nature of the responsive documents, dates, correspondents etc.) that might be relevant to the requesters need, even if the content is not released.
Issues: peer review, international relations, Vaughn index