Reading a patent search report as a state-of-the-art document

Technical note — Fabrice Trollet

Summary. A patent search report places earlier documents against the claims of an application, passage by passage, and classifies them by category. Its method is close to what an expert expects from the "state of knowledge" section of a French research tax credit claim: a dated document, a precise passage, an explicit consequence. This note describes what such a report contains, what it proves and what it does not.

What a search report contains

The international search report (form PCT/ISA/210) lists the documents that the searching authority considers relevant. For each one it gives:

• the reference of the document and its date;
• the passages concerned;
• the claims of the application to which the document relates;
• a category, designated by a letter.

The categories, in the words of the form

The legends below are copied from the form.

• « "A" document defining the general state of the art which is not considered to be of particular relevance »
• « "X" document of particular relevance;; the claimed invention cannot be considered novel or cannot be considered to involve an inventive step when the document is taken alone »
• « "Y" document of particular relevance;; the claimed invention cannot be considered to involve an inventive step when the document is combined with one or more other such documents, such combination being obvious to a person skilled in the art »

The form also defines categories E, L, O, P, T and "&".

What the report proves, and what it does not

The report establishes that, on a given date, the searching authority considered a given passage of a given document relevant to a given claim. It is neither a decision on the validity of the patent nor an assessment of the quality of the document cited. The claims finally granted may differ from those of the application searched, and nothing in the report establishes a causal link between a citation and an amendment of the claims.

The parallel with a research tax credit claim

A research tax credit claim must show that the solution could not be deduced from the state of knowledge. The discipline of the search report is useful here: every statement about the state of the art refers to a dated document and a precise passage, and the consequence drawn from it is written, not implied.

An example

Example chosen because the author of this note is the author of the document: it is public, and its analysis concerns no client's file.

In the international search report of application PCT/EP2022/050269 (search completed on 29/04/2022), the paper presented by the author at the ERTS 2020 congress is classified in category X for claims 1 and 9, the passages concerned being "paragraph [00IV] – paragraph [000V]", i.e. sections IV and V of the paper. The same report classifies two other documents in category X. The US patent of the same family, US 12,091,051 B2, was granted on 17 September 2024.

Sources: search report published with WO 2022/179759; registry of references.

Sources last checked: 29/09/2026.