Australia is one of the few major jurisdictions to retain a “best method” requirement for patent specifications, which necessitates that applicants disclose the best method known to them of performing the invention (Knowledge Element).[i] In a controversial decision, the Federal Court found in 2018 that, in the case of divisional applications, the Knowledge Element is to be assessed at the time of filing the divisional application. Last week, the Federal Court issued a contrary decision, finding the Knowledge Element for divisional applications is to be assessed at the effective filing date derived from the ultimate parent application.
The “best method” divisional controversy
Australia’s best method requirement is controversial in and of itself, having resulted in revocation of several patents in recent years despite those patents providing sufficient disclosure of the invention.[ii] In this regard, the rationale for the best method requirement, being full consideration to the public in exchange for the grant of a monopoly,[iii] may have made sense when the disclosure requirement for sufficiency was a low threshold. However, with the introduction of a European-style sufficiency requirement into Australian law in 2013, the best method requirement was arguably rendered obsolete.
Until 2018, it was widely accepted that the Knowledge Element for divisional applications was to be assessed at its effective filing date (i.e., the filing date of its ultimate parent application). Then came White J’s decision in Dometic Australia Pty Ltd v Houghton Leisure Products Pty Ltd [2018] FCA 1573 (Dometic), the first to directly consider the Knowledge Element for divisional applications. Dometic, which we discussed here, turned conventional wisdom on its head, putting numerous divisional patents and applications at risk of invalidity for failure to disclose any “better” method arrived at by the applicant between filing the parent and divisional applications.
Not only did this change in approach create headaches for applicants and patent attorneys alike, it also created a dual standard for applicants, whereby applicants who retained control of their parent applications were held to a higher standard of disclosure when filing divisional applications than assignees or licensees who were not privy to better methods developments by the original applicant since the parent application was filed. It also begged the question whether third party improvements owing nothing to the applicant ought to be disclosed in divisional applications at filing.
The controversy addressed
Patent attorneys in Australia breathed a collective sigh of relief when Moshinsky J handed down the Federal Court’s judgement in The NOCO Company v Brown and Watson International Pty Ltd [2025] FCA 887 (NOCO). While it was unnecessary to do so having already found that the claims of the divisional patent at issue lacked an inventive step, his Honour nonetheless (helpfully) considered the best method ground for completeness.
While Moshinsky J did not go so far as to stay that Dometic is “plainly wrong“,[iv] his Honour’s reasoning clearly indicates that is the case. The starting point for both decisions was Rescare Ltd v Anaesthetic Supplies Pty Ltd [1992] FCA 537 (Rescare), in which Gummow J considered in obiter dicta that the relevant date for assessing the Knowledge Element for an Australian national phase application was the international filing date, being the “date from which the term of the patent runs”.[v] The Full Federal Court in Pfizer Overseas Pharmaceuticals v Eli Lilly & Co [2005] FCAFC 224 (Pfizer) later commented on Rescare as follows.[vi]
The date as at which the best method known to the applicant is to be identified is conceptually distinct from the date by which the specification’s full description of the invention must include a disclosure of it. The parties correctly proceeded on the basis that it is the best method known to the applicant as at the filing date that must be disclosed. In Rescare, Gummow J expressed the opinion (at ALR 223; IPR 135) that this was so under s 40 of the 1952 Act, and s 40(2)(a) is to the same effect as s 40(1)(a) of the 1952 Act.
White J relied on this passage in Dometic as basis for the finding that the date for assessing the Knowledge Element in divisional applications is different from that for assessing sufficiency of disclosure. However, Pfizer was also concerned with whether the best method could be added by amendment after the complete specification filing date.[vii] While Moshinsky J incorrectly interpreted Pfizer as supporting the proposition that, at the relevant time, the best method could not be added to the specification by amendment,[viii] his Honour did not consider there to be any inconsistency between Rescare and Pfizer.
Further, unlike White J, Moshinsky J had regard to the Full Federal Court in Mont Adventure Equipment Pty Ltd v Phoenix Leisure Group Pty Ltd [2009] FCAFC 84 (Mont Adventure), which construed the phrase “the filing date of the complete application” in relation to a divisional application as being the filing date of the parent application.[ix]
In view of the decisions in Rescare, Pfizer and Mont Adventure, Moshinsky J did not consider there to be any good reason why the Knowledge Element for divisional applications should not be assessed as at the filing date of the ultimate parent application.
Status quo restored?
The Dometic decision caused a fundamental shift in patent practice in Australia, as well as a fundamental misalignment between the timing for disclosure of the best method and sufficiency of disclosure (and support). The NOCO decision goes a long way towards restoring the pre-2018 status quo in relation to assessing the Knowledge Element for divisional applications. However, while Moshinsky J’s approach in NOCO represents a more consistent and pragmatic approach to that of White J in Dometic, applicants should remain vigilant as the matter remains open to appeal (or separate consideration by the Full Court).
If you would like any more information about best method or the disclosure requirements for patent specifications in Australia, please contact Claire Gregg.
[i] Patents Act 1990 (Cth), s 40(2)(aa)
[ii] See, e,g., Les Laboratoires Servier v Apotex Pty Ltd [2016] FCAFC 27, Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd [2017] FCAFC 138, Zoetis Services LLC v Boehringer Ingelheim Animal Health USA Inc [2024] FCAFC 145
[iii] Pfizer at [374]
[iv] NOCO at [338]
[v] Rescare at [76]
[vi] Pfizer at [375]
[vii] It is also worth noting the context for “conceptual distinctness” in Pfizer, which can be found at [342]: “The High Court in Lockwood Security had been at pains to identify ‘that the grounds of invalidity themselves are, and must be kept, conceptually distinct’”
[viii] NOCO at [384]; Notably, addition of the best method by amendment is not permitted for applications and patents for which examination was requested on or after 15 April 2013
[ix] Mont Adventure at [14] per Emmett J