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. Definitions, Notes and Warnings

Date Published

The information provided in the definitions, warnings and notes in the CPC scheme is another significant improvement compared to the IPC. They are a useful, indispensable source of information and can assist greatly during patent classifying and searching processes.

Such information helps clarify the intended scope and meaning and provides useful pointers to other CPC places.


Definitions are indicated by 'D' (example below) and are available for most CPC classes, subclasses, main groups and some subgroups.

Definitions provide additional explanations and guidance for subject-matter that is not available in the scheme, including:

  • Definition statement: a plain-language explanation of the subject-matter appropriate for classification in the specific area covered by the definition
  • Clarifies the scope of the specific symbol, for instance by incorporating categories of invention not explicitly mentioned in the title, but also covered by it
  • References: similar to the IPC, limiting and non-limiting references of the CPC section can be found in both title and definition
  • Glossary of terms: provides detailed explanation for particular words or expressions having a specific meaning in the art; usually found in definition of subclasses
  • Synonyms and keywords: this is an optional section, intended for searchers establishing a search strategy
  • Relationships with other classification places (usually at subclass level)
  • Special rules of classification (within the place)

Definitions are normally not used for indexing-only subclasses (e.g. A23V, F05B) and for the whole of section Y (e.g. Y04S, Y10S).


Notes are indicated by  'i' (example below)

  • they define or explain specific words, phrases or the scope of places
  • are associated with a particular section, class, subclass, group, subgroup, heading, etc.

Notes found in relation to a group override other indications relating to the corresponding class.

In the notes:

  • the scope of places is explained
  • the way of classifying subject-matter is indicated.


Warnings are indicated by '!' (example below)

Warnings help draw the user’s attention to incompleteness or deviations from the standard practice, for example:

  • reclassification is in progress
  • groups not present in the current version of the CPC or CPC groups entering into force or no longer in force

Due to its nature, the content of warnings is changed and updated constantly.


Schemes are indicated by 's' (example below)

Clicking on this icon will open the corresponding CPC scheme in PDF format

These PDF files can be accessed directly from the official CPC website.

Amended Reasons

Amended Reason Date Amended
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