In a decision of January 14, 2016 (T 2451/13 ) the standard of proof for the publication date of a document has been amended. For a brochure which is usually to be distributed in the course of business and which bears a copyright date the standard for the burden of proof is usually a balance of probability. This standard, however, is not applicable if the document is originating from an opponent or subsidiary thereof. The Board of Appeal has ruled: “If the publication date of a document originating from an opponent (or a subsidiary thereof) is in dispute, the opponent must prove that date “up to the hilt”. The yardstick for this proof is that of “beyond reasonable doubt” rather than “absolute certainty”. The decision is interesting under a further aspect: the Board of Appeal did not object that the Opposition Division has accepted a ground for opposition which was late-filed namely after expiry of opposition period by reasoning that the late filed ground was a reaction to the publication of a pertinent Board of Appeal decision.