The following provides examples of possible strategies for searching using classification symbols. In-depth examples are included below. It is highly recommended to use the CPC as a starting point and primary patent search tool for classification searching (for example, strategies 1 - 3).

Approximately 40 million documents in EPODOC/Espacenet have CPC symbols. There are multiple ways to search using the CPC in EPODOC or Espacenet and each technique has a place in a complete search. The CPC suits a staged and iterative approach to searching the prior art.

The five strategies are shown in the diagram with a decreasing level of preciseness. Strategy 1 is the most precise and Strategy 5 is the least precise. In an iterative searching process, the key is to start with a more precise approach and slowly expand the search as needed.

Strategy 1

When to use

The CPC symbol or combination of CPC symbols is precise enough that it provides good coverage of the inventive aspects of an invention for the purposes of a search. No keywords are needed, meaning that foreign language documents can be easily found. The number of results with a narrow CPC search can also be reasonable in terms of performing an efficient search.

Advantages:

uses only CPC symbols, no keywords;
locates documents without an abstract (old US documents); and
locates non-English documents, particularly in DE and FR collections

Coverage

Using this strategy, the search will cover approximately 40+ million documents classified in the CPC, including full EP, US, WO, GB, DE, FR collections and parts of other national collections including CN, KR, AU, and CA.

Syntax

Step 1: Select the PATENW database in EPOQUE

Step 2: Enter selected CPC symbol(s)

a single CPC symbol: /C CPC
combining several CPC symbols using the AND operator: /C CPC1 and CPC2; and/or
combining several CPC symbols using the AND and OR operators: /C (CPC1 or CPC2) and (CPC3 or CPC4).

Note to always consult definitions, warnings, and notes if they are available.

Strategy 2

When to use

Strategy 2 may be employed when a first iteration did not yield highly relevant prior art. It should also be used when the CPC definition is of a wider scope than the claimed invention or the number of documents classified under the CPC symbol(s) is too large for an efficient search.

Aim

With this strategy, the aim is to use both English language PATENW abstracts and Derwent abstracts (in WPIAP) of CPC-classified documents. Some documents from collections such as DE, FR, or old US, may not have original English abstracts but their records in WPIAP may contain Derwent English abstracts.

Disclosures in Derwent abstracts are generally more useful as they are prepared by subject matter experts who read the patent document and summarise the disclosure in a structured form that identifies the inventive concept and advantages over the prior art. Original abstracts, on the other hand, are prepared by applicants and generally use subjective or irregular language and may not always explain the inventive concept in a precise or consistent manner.

Coverage

Full EP, US, WO, GB, DE, FR collections and a small part of national collections CN, KR, AU and CA (documents with an original abstract and/or a Derwent abstract only).

Syntax

Step 1: Select the PATENW database in EPOQUE (..FI PATENW)

Step 2: Enter selected CPC symbol(s) (alone or in combination as detailed in Strategy 1)

Step 3: ..FAMEX

Step 4: Enter keywords followed by the /$ABS field qualifier.

Strategy 3

When to use

Strategy 3 is useful when Strategies 1 and 2 do not produce highly relevant prior art, or when features being searched are unlikely to be disclosed in abstracts.

Aim

In this strategy, the aim is to utilise the full disclosure of English documents.

Coverage

CPC-classified documents that have full text in English, especially EP, US, WO and GB.

Syntax

Step 1: Select the PATENW database in EPOQUE (..FI PATENW)

Step 2: Enter selected CPC symbol(s) (alone or in combination as detailed in Strategy 1)

Step 3: ..FAMEX

Step 4: Enter keywords.

Strategy 4

When to use

Strategy 4 is useful when highly relevant prior art has not been found and the search is now expanded to using the IPC and CPC at the same level in the hierarchy with the IPC. The warnings state a reclassification is occurring and less precise CPC symbols should be searched (a consequence is the search needs to be expanded to more general and less precise CPC symbol(s)), and to search non-CPC classified material using the IPC (for example Japanese documents, prior to 2016 Chinese documents, Russian documents, and portions of Korean and Australian prior art).

Aim

In this strategy, the aim is to search in collections with incomplete or no CPC classification, especially unique collections from Australia, Canada, Korea, Japan, and China.

Coverage

Non-CPC documents, especially unique collections of AU, CA, JP, CN, and KR

Syntax

Step 1: Select the PATENW database in EPOQUE (..FI PATENW)

Step 2: Enter selected IPC and CPC symbol(s) (alone or in combination as detailed in Strategy 1)

Step 3: ..FAMEX

Step 4: Enter keywords followed by the /$ABS field.

Strategy 5

When to use

Strategy 5 is useful when the search needs to be expanded to broader CPC symbol(s), at the IPC-equivalent level.

Aim

In this strategy, the aim is to search in collections with incomplete or no CPC classification but with full text description in English.

Coverage

Documents without CPC symbols but with full text in English, especially unique collections of AU and CA.

Syntax

Step 1: Select the PATENW database in EPOQUE (..FI PATENW)

Step 2: Enter selected IPC and CPC symbol(s) (alone or in combination as detailed in Strategy 1)

Step 3: ..FAMEX

Step 4: Enter keywords.

Amended Reasons

Amended Reason	Date Amended
	18 Oct 2023