The phrase “incorporated by reference” is found quite commonly in patent specifications, especially in US-originating specifications where it is used to supplement the disclosure by importing the entire content of the “reference document”.

EPO Examiners generally request that the phrase “incorporated by reference”, or similar, be deleted wherever it appears in a patent specification. The rationale is that a European patent specification should, with regard to the essential features of the invention, be self-contained, i.e. capable of being understood without reference to any other document (EPO Guidelines F-III, 8). Accordingly, EPO Examiners take the view that:

  1. if the subject-matter contained in the reference document is not essential for carrying out the invention from a sufficiency perspective (Article 83 EPC), the phrase should be deleted (though not the reference to the document itself). This is a standard request before grant in Europe and causes no issues;
  2. if the subject-matter contained in the reference document is essential for carrying out the invention from a sufficiency perspective, the phrase should be deleted, and the relevant subject-matter of the reference document should instead be explicitly introduced into the specification, so that the application meets the requirements of sufficiency.

The latter situation (b) is not always straightforward, since the introduction of the relevant subject-matter from the reference document is subject to the following restrictions:

The description of the invention as originally filed must leave no doubt to a skilled reader that:

  1. protection is or may be sought for the features which are to be imported;
  2. such features contribute to solving the technical problem underlying the invention;
  3. such features at least implicitly clearly belong to the description of the invention contained in the application as filed and thus to the content of the application as filed; and
  4. such features are precisely defined and identifiable within the disclosure of the reference document.

If these conditions (i) – (iv) are met, the introduction of the relevant subject-matter is allowable and causes no issues. However, if these conditions (i) – (iv) are not met, the introduction of the relevant subject-matter would constitute added subject-matter under Article 123(2) EPC. This can leave the applicant in an impossible position between, on the one hand, having an insufficient patent specification if the relevant subject-matter is not introduced, and, on the other hand, receiving an added subject-matter objection if the relevant subject-matter is introduced.

What constitutes a reference document?

One further point of note is that if the reference document was not available to the public on the date of filing of the European application, its content can only by considered for introduction into the European application if, as discussed in EPO case T 737/90:

  1. a copy of the reference document was available to the EPO on or before the date of filing of the application; and
  2. the reference document was made available to the public no later than on the date of publication of the application.

In a recent EPO case, T 521/10, the appellant relied on three reference documents, WO 00/46680 [“R1”], US 09/378184 [“R2”] and US 09/378220 [“R3”], all incorporated by reference, to provide an enabling disclosure for the sufficiency of claim 1. The application in suit had a priority date of 16 January 2000 and a filing date of 12 January 2001, and was published on 19 July 2001.

R2 and R3 did not fulfil condition (II) set out above, as the earliest publication date for R2 and R3 was 7 November 2002, i.e. later than the publication date of 19 July 2001 of the application in suit. Accordingly, R2 and R3 were held to be invalid reference documents whose content could not be imported to enable the invention of claim 1. R1 was considered to be the only valid reference document of the three documents incorporated by reference. Unfortunately, however, R1 had its own problems, as R1 was not referred to in the priority application. Therefore, the priority date for claim 1 was not valid because claim 1 was not enabled by R1 in the priority application. The effective filing date for claim 1 was 12 January 2001, which was after the publication of R1 on 10 August 2000, rendering R1 as prior art against claim 1.

Recommended Practice Points

  1. If a reference document (“incorporated by reference”) is essential to understanding or carrying out an invention, ensure that it is referred to and described in the priority application. We would strongly recommend including the actual text/drawings from the reference document essential to understanding or carrying out the invention, rather than relying on incorporation by reference.
  2. Ensure that the reference document will be published before the publication date of the patent application, or else it will not be considered as a valid reference document.