Extrinsic materials

Jusand Nominees v Rattlejack [2023] FCAFC 178

An issue in this infringement case was whether the patent specification disclosed and supported the invention9.  The statutory requirements had been amended to align our law with offshore practice.  On the basis they were ‘ambiguous’ under s 15AB(1)(b)(i) of the Acts Interpretation Act, Perram J had regard to extrinsic materials describing the offshore practice.  Those materials clarified the new requirements. 

At common law, regard is had in any event to these materials from the outset, ambiguity or not10.  Perram J raised if the search for purpose is confined to the text.  Evidence of purpose may be found externally, but that purpose always resides in the Act.

This principle is from Episode 103 of interpretation NOW!


9 ss 40(2)(a) & 40(3) of the Patents Act 1990 (Cth).

10 CIC Insurance (1997) 187 CLR 384 (408), Bay Street [2020] FCAFC 192 [5].