Glossary
French: marque notoire
A well-known mark (marque notoire or marque notoirement connue) is a mark that is so widely known that it is protected even without registration. It is the French embodiment of Article 6bis of the Paris Convention (reinforced by the TRIPS Agreement), which obliges member states to protect marks that are notorious on their territory regardless of whether they appear on the national register.
This is one of the sharpest divergences between French and US practice. France and the EU are otherwise strict registration systems — rights come from filing, not use. The well-known mark is the narrow exception: a mark that has never been filed in France can still block and defeat a later French application, purely on the strength of its notoriety with the French public. There is no French common-law trademark, but there is this statutory island of unregistered protection.
In the United States, by contrast, unregistered marks are routinely protected through common-law use and Section 43(a) — but the specific Paris Convention “famous marks” doctrine for foreign marks not used in the US is weak and contested: several federal courts have declined to recognize a standalone well-known-marks cause of action for marks with no US use. So the direction of the asymmetry is worth noting: a foreign owner may find its unregistered fame counts for more in France than a comparable claim would in the US.
French practitioners keep two neighboring notions distinct, and the difference is practical:
Confusing the two is a common drafting error; the statutory bases and the reach are different.
Imagine a major international beverage brand that has never bothered to file in France because it does not yet sell there, but which every French consumer would instantly recognize. If a local company files that name for soft drinks, the foreign owner can rely on the well-known-mark doctrine to oppose or invalidate the French filing, even with no French registration of its own — provided it can prove genuine notoriety with the French public.
Well-known marks appear in the catalogue of prior rights studied under third-party rights and relative grounds, and they can ground an INPI opposition or feed an invalidity action. Because notoriety is a question of evidence, proving it overlaps with the proof work described under evidence of infringement in France. Contrast it carefully with the reputed mark.