A non-conventional trademark, also known as a nontraditional trademark, is any new type of trademark which does not belong to a pre-existing, conventional category of trade mark, and which is often difficult to register, but which may nevertheless fulfill the essential trademark function of uniquely identifying the commercial origin of products or services. The term is broadly inclusive as it encompasses marks which do not fall into the conventional set of marks (e.g. those consisting of letters, numerals, words, logos, pictures, symbols, or combinations of one or more of these elements), and therefore includes marks based on appearance, shape, sound, smell, taste and texture. Non-conventional trademarks may therefore be visible signs (e.g. colors, shapes, moving images, holograms, positions), or non-visible signs (e.g. sounds, scents, tastes, textures). Trends and issues Certain types of non-conventional trademarks have become more widely accepted in recent times as a result of legislative changes expanding the definition of "trademark". Such developments are the result of international treaties dealing with intellectual property, such as the Agreement on Trade-Related Aspects of Intellectual Property Rights, which sets down a standardised, inclusive legal definition. Single colour trademarks, motion trademarks, hologram trademarks, shape trademarks (also known as three-dimensional trademarks or 3D trademarks), and sound trademarks (also known as aural trademarks), are examples of such marks. In the United Kingdom, colours have been granted trademark protection when used in specific, limited contexts such as packaging or marketing. The particular shade of turquoise used on cans of Heinz baked beans can only be used by the H. J. Heinz Company for that product. In another instance, BP claims the right to use green on signs for petrol stations. In a widely disputed move, Cadbury's (confectioners) has been granted "the colour Purple". In the United States, it is possible, in some cases, for color alone to function as a trademark. Originally, color was considered not a valid feature to register a trademark Leshen & Sons Rope Co. v. Broderick & Bascom Rope Co., 201 U.S. 166 (1906). Later, with the passage of the Lanham Act the United States Supreme Court in the case of Qualitex Co. v. Jacobson Products Co., 514 U.S. 159, 165, 115 S.Ct. 1300, 1304, 131 L.Ed.2d 248 (1995) would rule that under the Lanham Act, subject to the usual conditions, a color is registrable as a trademark. The right to exclusive use of a specific color as a trademark on