The High Court has upheld a claim for extended passing off brought by the producers of “Total Greek yoghurt” against the producers of a yoghurt product made in the US and sold in the UK as Greek yoghurt. The court held that a substantial proportion of buyers of the product described as Greek yoghurt believed that it came from Greece and that it mattered to them that it did. It was irrelevant that Greek yoghurt buyers formed a modest proportion of yoghurt eaters as a whole. It followed that the defendants’ description of their product as Greek yoghurt was a misrepresentation which was likely to lead to the erosion of the distinctiveness of the phrase Greek yoghurt. The decision provides clarification that the consumers, in the minds of which a product class denoted by a trade name needs to be defined, need not be the whole or even a majority of the public, but need only be a significant section of it (which might be a modest one) for a claim in passing off to be made out. It also provides yet another reminder that survey questions need to be carefully crafted, with their possible responses worked through, to ensure that they have probative value. Fage UK Ltd and another v Chobani UK Ltd and another  EWHC 630 (Ch), 26 March 2013. If you feel that your rights have been damaged by a passing off like this or if you need help drafting or reviewing survey questions then contact Christopher Evans.