Welcome to the new version of the Patents Manual. Please note there are changes to the numbering and sequence of the chapters and pages in the manual. You are encouraged to take the time to explore and familiarise yourself with this new structure. Level of disclosure required (enabling disclosure, clear and unmistakable directions etc.)

Date Published

Key Legislation:

Patents Act:

  • s7 Novelty, inventive step and innovative step  
  • s24 Validity not affected by making information available in certain circumstances
  • Schedule 1 Dictionary

Patents Regulations:

  • reg 2.2 Information made publicly available--recognised exhibitions
  • reg 2.2A Information made publicly available--learned societies
  • reg 2.2B Information made publicly available--reasonable trial of invention
  • reg 2.2C Information made publicly available--other circumstances
  • reg 2.2D Information made publicly available without consent--period

Referenced Acts:

  • s2B Acts Interpretation Act

Level of Disclosure Required

Practical Utility

There must be sufficient directions in the prior art for a skilled addressee to identify the claimed invention and to put it into practice. Therefore, the information in a citation must be equivalent to that provided in the complete specification under examination, for the purposes of "practical utility".

Non-Literal Disclosure

A disclosure less than a literal disclosure can act as an anticipation and a clear recommendation could be a sufficient disclosure.

However, a disclosure will not be an anticipation if the skilled addressee has to be inventive in applying the teaching of the earlier disclosure (i.e. a non-enabling disclosure) or in arriving at the essential integers of the claim.

Clear and Unmistakable Directions

Examiners must give consideration to the teachings of the prior art, that is, what would the skilled addressee have done on reading the citation?

A prior disclosure will only anticipate a claim if it contains clear and unmistakable directions to do/produce the alleged claimed invention. Hence, after having read the prior disclosure, the skilled addressee would, rather than could, have produced all the essential features of the claim.

If a prior disclosure contains a direction that can equally be carried out in a manner that would infringe the claim in question, as well as in a manner that would not infringe the claim in question, it will not anticipate the claim (although it may be relevant for inventive step).

Mere Paper Anticipations

It is sometimes stated that an anticipation based solely on a document is a 'mere paper anticipation' and that an especially strict interpretation is required.

The concept of 'mere paper anticipation' arose from Metropolitan-Vickers v B.T.H. Co. Ltd (1926) 43 RPC 76 at page 93, where, inter alia, it was stated:

"In Otto v Linford, (1881) 46 LT at page 35 it was held that the later invention must be described in the earlier publication that is held to anticipate it; it is not sufficient that, if a machine had been made according to such description, it would have produced a result, not to be gathered from the description, which would have disclosed such invention."

Thus, the concept of 'mere paper anticipation' operates to exclude suggestions that if the citation had been used, something different or additional would have resulted and the something is therefore disclosed. Examiners should note that such suggestions implicitly require evidence of actual use of the citation before the priority date.

Enabling Disclosures

An enabling disclosure is one that provides enough information to allow the person skilled in the art to put the invention into practice, without the need for further experiments. Even if a skilled addressee is "clearly and unmistakably" directed to an invention from the prior art, there must still be sufficient disclosure.

Examiners should assume in the first instance that a citation is an enabling disclosure, unless this is manifestly not so. If the applicant argues against a novelty objection on the basis that the disclosure was not enabling, the onus is on the applicant to demonstrate this is the case.

Where a citation indicates the substance in question was made, there is an increased presumption that the disclosure is enabling.

Legal principles and case law

Practical utility

See Hill v Evans (1862) 6 LT 90.

Non-literal disclosure


  • Hill v Evans (1862) 6 LT 90
  • Lord Reid in Van der Lely NV v Bamfords Ltd [1963] RPC 61
  • WR Grace and Co v Asahi Kasei Kogyo Kabushiki Kaisha (1993) AIPC 90-974
  • Nicaro Holdings v Martin Engineering 16 IPR 545 at page 563.

Clear and unmistakeable direction


  • General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457 at pages 485-486.
  • Canadian General Electric Co., Ltd v Fada Radio Ltd (1930) 47 RPC 69 at page 90.

Enabling disclosures


  • Nicaro Holdings Pty Ltd v Martin Engineering Co 16 IPR 545 at page 549.
  • Acme Bedstead Co Ltd v Newlands Bros Ltd (1937) 58 CLR 689,
  • Asahi Kasei Kogyo KK's Application [1991] RPC 485
  • Genentech Inc's (Human Growth Hormone) Patent [1989] RPC 613)


Amended Reasons

Amended Reason Date Amended

Published for testing

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