Disclaimers - Examples of global (dis)harmony

T. Yamada[1] (JP), K. Kitatani[1] (JP), C. Köster[2] (DE)

Successfully introducing disclaimers into claims of a European patent application or a European patent is not easy. This is true for “undisclosed disclaimers” as well as for “disclosed disclaimers”. In G 1/16, the Enlarged Board of the European Patent Office elaborated that “undisclosed disclaimers” relate to the situation in which neither the disclaimer itself, nor the subject matter excluded by it, have been disclosed in the application as filed.[3] In contrast, “disclosed disclaimers” relate to the situation in which the disclaimer itself might not have been disclosed in the application as filed, but the subject-matter excluded by it has a basis in the application as filed.[4] The requirements for an undisclosed disclaimer being allowable are outlined in G 1/16, while the requirements for a disclosed disclaimer being allowable are outlined in former decision G 2/10.[5] It would seem that the respective requirements are rather strict, and we asked ourselves whether disclaimers might be handled in a more lenient way elsewhere. In this article, we thus look at requirements for introducing undisclosed disclaimers and disclosed disclaimers, respectively, in other jurisdictions. This journey to other jurisdictions brings us first to Japan, where undisclosed disclaimers have gained popularity over the last years, and then takes us back to Europe by looking at the requirements for a disclosed disclaimer in Germany.

I. Japan - Undisclosed disclaimer

Japan had previously long maintained the practice that an undisclosed disclaimer should only be used in exceptional cases, such as for restoring novelty over accidental anticipation in a prior document. However, the Grand Panel of the Intellectual Property High Court (IPHC) dramatically shifted the landscape of this practice in Japan when it issued a notable ruling on the admissibility of disclaimers (Heisei 18 (Gyo-Ke), No. 10563; judgment rendered on May 30, 2008). In summary, the Grand Panel eased the admissibility of undisclosed disclaimers by holding that amendments are to be allowed unless they add new technical matter in relation to the technical matter taken from the specification or drawings as viewed by a person skilled in the art.

Since then, disclaimers have been used as an easy manoeuvre to overcome prior art issues, including lack of inventive step, during prosecution before the Japan Patent Office (JPO). Nevertheless, even after the above-noted Grand Panel case, the JPO has made no substantial change to the JPO’s Examination Guidelines. In particular, the Guidelines still stipulate that examples of admissible undisclosed disclaimers include cases wherein "the claimed invention is likely to lack novelty and the like (Article 29, paragraph 1, Article 29bis or Article 39) (Note: including lack of novelty rejections, rejections over secret prior art and double-patenting rejections)" while refraining from explicitly mentioning the lack of inventive step rejection.

As such, it had been uncertain whether an undisclosed disclaimer could be regarded as establishing the existence of inventive step. However, on 25 September 2014, a notable court ruling was handed down by the IPHC regarding a disclaimer introduced by the proprietor as the defendant in the following claim of JP Pat. No. 4768217:

“A transparent film comprising an ethylene/vinyl acetate copolymer, and acid acceptor particles dispersed in the copolymer,
wherein the acid acceptor particles are a metal oxide (provided that an oxide of Sn, Ti, Zn, Zr, Fe, Al, Cr, Co, Ce, In, Ni, Ag, Cu, Pt, Mn, Ta, W, V, or Mo is excluded), a metal hydroxide or a mixture thereof,
wherein the content of the acid acceptor particles is 0.5 wt% or less of the copolymer, and
wherein an average particle size of the acid acceptor particles is 5μm or less,
wherein the content of vinyl acetate in the ethylene/vinyl acetate copolymer is 20 to 36 wt%,
wherein the ethylene/vinyl acetate copolymer is further cross-linked with a cross-linker, and
wherein the transparent film is characterized by being used as a sealing film or a laminated glass for a transparent adhesive layer for a solar cell.”

The disclaimer "an oxide of Sn, Ti, Zn, Zr, Fe, Al, Cr, Co, Ce, In, Ni, Ag, Cu, Pt, Mn, Ta, W, V, or Mo" was introduced as an undisclosed feature during invalidation trial proceedings in order to render the claim inventive because a prior art document had disclosed these oxides as functional superfine particles. The JPO had allowed this "undisclosed" disclaimer, regarding it is duly satisfying the requirements for correction of claims, and, therefore, maintained the patent.

Dissatisfied with this decision, the plaintiff appealed to the IPHC, arguing that "the correction (a) (Note: the disclaimer as described above) deviates from the purpose of corrections which are only allowed to exclude the scope overlapping with the prior art".

The IPHC accepted the appeal but rejected the plaintiff's argument against the disclaimer for the following reasons:

"Corrections are allowed as long as they are for the purposes of Article 134 and do not introduce technical matter... and therefore the fact that such corrections were made to overcome the lack of inventive step as a ground for invalidation, should not influence the admissibility of the corrections".

The IPHC went on to say that "third parties could not face disadvantages from the correction as a person skilled in the art could easily understand that, with regard to the types of metal oxides in the invention, specific ones as the acid acceptor particles were excluded”.

Such court ruling has been taken as giving a de facto green light for the use of disclaimers as a measure to establish inventive step, and practitioners are now able to disclaim undisclosed features in Japan as an easy solution to prior art issues.[6]

Obviously, this is contrary to the European practice in which a disclaimer, which is, or becomes relevant for, the assessment of inventive step constitutes added matter and is, consequently, not allowable.[7]

II. Germany – Disclosed disclaimer

The latest view on disclaimers by the Federal Court of Justice of Germany is the order “Phosphatidylcholin”.[8] The underlying case concerned an application for a patent filed with the German Patent and Trademark Office.[9] The claim at issue read in the Federal Court of Justice’s structuring as follows:[10]

  1. Cosmetic, non-therapeutic use of
    1. 5 – 30 wt.% NaCl
    2. 5 – 30 wt.% glycerine
    3. in hand protection creams, cleansing milks, sun protection lotions, nutrient creams, day or night cremes for strengthening the barrier function of the skin,
  2. wherein the indications of weight refer to the total weight of the compositions,
  3. wherein these compositions are free from phosphatidylcholine.

Feature no. 3 formed the disclaimer in dispute. More specifically, the language of feature no. 3 is disclaiming the presence of phosphatidylcholine, but this language was not found in the application as filed. Phosphatidylcholine was, however, mentioned by its alternative name lecithin as one of various contemplated emulsifiers.[11] Hence, following the terminology of G 1/16, feature no. 3 amounted to a disclosed disclaimer.

The German Patent and Trademark Office refused the application for lack of support for feature no. 3 in the original disclosure. The applicant appealed to the German Patent Court, which dismissed the appeal, but granted leave to appeal on a point of law to the Federal Court of Justice.[12]

In its order, the Federal Court of Justice first emphasized that the Patent Court was right in starting from the standpoint that an application, which claims subject matter which goes beyond the content of the application as filed, must be refused in case this deficiency is not remedied upon invitation by the Examining Section.[13] The Federal Court of Justice then stated its own case law “Wundbehandlungsvorrichtung” on undisclosed, but merely limiting features, which do not jeopardize a patent’s validity in post-grant invalidity actions, needs not to be extended to pre-grant application procedures.[14]

The Federal Court continued with discussing the technical information provided to the reader by the application at issue. Based on this discussion, the Court concluded at marginal no. 24 of its order that there was no pointer in the original application to phosphatidylcholine as an essential or advantageous ingredient. The respective passage of the order reads in English translation as follows:

“c) There is accordingly no clue in the application documents that phosphatidylcholine is an essential constituent of the preparation or only that the addition thereof would be considered advantageous. This is confirmed by the fact that the preparations 1 to 3, which are listed in the description in an exemplary manner, each contain 5 wt.%. glycerine and 7 wt.% common salt, but no phosphatidylcholine.”

Overall, the Federal Court of Justice came to the conclusion that the introduction of feature no. 3 into the claim in dispute did not amount to an unallowable extension beyond the content of the application as originally filed.[15] In other words, the disclaimer was allowed.

An interesting side note in this context is that the Federal Court of Justice also discussed in its order the pertinent case law of the European Patent Office.[16] In particular, the then available case law of the Enlarged Board of Appeal of the European Patent Office on disclaimers was referenced.[17][18][19] The Federal Court of Justice took from that case law the message that a disclaimer, which excludes certain embodiments or ranges of a generally formulated feature, shall be not allowable in case the corresponding limitation is technically relevant. In the decided case, the Federal Court of Justice, however, saw no such technical relevance, and also found its own approach to be in line with the case law of the Enlarged Board of Appeal of the European Patent Office.[20]


It seems to be fair to say that the limits for allowability of both undisclosed and disclosed disclaimers set in the case law of the European Patent Office are comparably tight.

From the German practice, it can be learned that there can be room for manoeuvre within these limits, at least when it comes to disclosed disclaimers. This might require a somewhat generous assessment of the question whether an introduced disclosed disclaimer leads to a technically relevant limitation. However, the German Federal Court of Justice itself believes that its own approach is in harmony with the European Patent Office’s approach. Hopefully so.

The Japanese practice goes far beyond the limits of the European practice. Undisclosed disclaimers are allowable even if their purpose is to render the claimed subject matter inventive, which can offer a loophole for applicants encountering extremely similar prior art. However, the misuse of such undisclosed disclaimer should be avoided in some way. The Japanese approach therefore appears to be in disharmony with the European Patent Office’s approach, showing that the latter is not the only way of handling disclaimers, at least not from a global perspective.

  1. TMI Associates, Tokyo
  2. Banse & Steglich Patentanwälte PartmbB, München
  3. G 1/16, OJ EPO 2018, A70, at. No. 14 of the Reasons
  4. G 1/16, loc. cit., at. 15 of the Reasons
  5. G 2/10, OJ EPO 2012, 376
  6. The JPO’s Examination Guidelines have remained unchanged even since the court ruling.
  7. G 1/03, OJ EPO 2004, 413, headnote II.3
  8. BGH, Order of 25 July 2017 - X ZB 5/16 - Mitt. 2017, 493
  9. DE 101 23 771 A1
  10. BGH, loc. cit., marginal no. 9
  11. DE 101 23 771 A1, paragraph [0055]
  12. BPatG, GRUR 2016, 583
  13. BGH, loc. cit., marginal no. 17
  14. BGH, loc. cit., marginal no. 19; citing BGH, Order of 17 February 2015 - X ZR 161/12 – Mitt. 2015, 275
  15. BGH, loc. cit., marginal no. 25
  16. BGH, loc. cit., marginal no. 26
  17. G 1/03, loc. cit.
  18. G 2/03, OJ EPO 2004, 448
  19. G 2/10, loc cit.
  20. BGH, loc. cit., marginal no. 26