Chemical structure of drospirenone, the compound at issue in Bayer v. Sandoz.
Chemical structure of drospirenone, the compound at issue in Bayer v. Sandoz.

The Supreme Court of the Netherlands (De Hoge Raad) ruled on an interesting question of patent claim scope earlier this year.  The case, Bayer/Sandoz, ECLI:NL:HR:2016:196, involved a much-litigated patent on the synthesis of drospirenone, a component of some birth control products.

The question at issue was whether, because the claims mentioned only a ruthenium catalyst while the specification also disclosed the use of other metals as catalysts, the claims could be construed to encompass those other metals as well.

Rejecting this argument, the court adopted what is sometimes called the doctrine of “implied public dedication.” Under this doctrine, any inventive features that are specified in the specification but not explicitly claimed in the claims is surrendered to the public domain. This limits the applicability of the doctrine of equivalents: an equivalent of the invention that was discussed in the specification but not claimed is forever released to the public, while an equivalent not discussed in the specification may still be considered to be within the patent’s protected scope.

The implied public dedication doctrine is sometimes characterized as a claim construction principle. It doesn’t involve the kind of semantic inquiry that claim construction usually entails, but could be classified as a kind of pragmatic implicature.

In Dutch patent law, this decision is notable because it turns away from an earlier line of Dutch Supreme Court cases that took the opposite view: that subject matter was not disclaimed unless the patentee showed a clear intent to disclaim it.

But what I find really interesting here is the phrase the Dutch courts use to describe this principle. It’s a beautiful turn of phrase, rhythmic and concise:

Disclosed but not claimed is disclaimed.

As far as I can tell from Googling, this English phrase, which the Supreme Court and the lower court both carefully put in italics, is original in the Dutch courts. To the extent it turns up in English at all, it appears only in English-language reports about these Dutch court opinions.

The doctrine is of course a well-established one in many English-language jurisdictions, including the US and UK. But for the concept to be distilled into this crystalline turn of phrase, it had to be filtered into a foreign legal language and back out again.

This small example helps to show how valuable comparative inquiry can be — especially in fields like patent law that are so prone to unnecessary turgidity. Brevity and clarity are life and death in the law (and often in translation as well), and can be impossible to achieve as long as one is trapped in a single legal discourse.

Comparative law is often shrugged off, especially in the US, as a field with little if any practical importance to practitioners working in a single country. But as the Dutch courts’ delightful turn of phrase shows, watching how similar legal principles are refracted through different legal languages can make possible a clarity that would otherwise be out of reach.