6.1.7.1.2 Overview of the Hierarchy

Date Published

Hierarchy for interpretation of terms or phrases in PCT applications

A hierarchy for how terms or phrases are to be interpreted is set out by the PCT International Search and Preliminary Examination Guidelines (PCT/ISPE/GL at paragraph 5.20).

  • If there is a special meaning by explicit definition or otherwise (which equates to ‘dictionary definition’), then that meaning should be used to understand the term or phrase.

  • If there is no special meaning, use the ordinary meaning as understood in the technology by the person skilled in the art.

  • If there is no ordinary meaning and no special meaning, use the everyday (non-technical) meaning to interpret the term or phrase.

An underlying principle in claim interpretation relates to the person skilled in the art. Terms and phrases in a claim are read by the person skilled in the relevant art, taking into account the priority date (see the 2nd sentence of PCT/ISPE/GL paragraph 5.32).

Comparison of claim interpretation in PCT and national examination

The hierarchy in the PCT guidelines is similar to claim construction in national examination where the plain meaning (everyday meaning) is used to construe terms, except where either of the following apply:

  • There is a well-recognised meaning in the art (ordinary meaning).

  • The meaning has a dictionary or explicit meaning in the application (special meaning).

The principal difference between the PCT guidelines and construction in national examination is that the PCT guidelines does not permit any discretion as to the interpretation of the words with respect to the intent of the invention. See 5.5.3 Rules of construction for a patent specification for further information about construction of claims in national examination.

Amended Reasons

Amended Reason Date Amended

Edited for better readability and accessibility. Edited for consistency with Style Manual. Added subheadings. Updated link text.

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