Bass beer started stamping a big red triangle on their barrels to let people know the beer inside the barrel was Bass beer. They did this because a lot of unscrupulous beer makers in the UK were copying beer to sell and tried to make sales based on the good name of another. The inferior beer was being sold to patrons without their knowledge of the scam.
Many of Bass beer’s competitors simply copied the big red triangle as well. Luckily, the British Trade Marks Registration Act of 1875 was passed giving companies legal action when others stole their brand for profit. It is believed that some poor sole from Bass slept outside the doorstep of the trademark office the night before the act was to be enacted so that Bass would have the first legally filed trademark.