Signs can be found in a diversity of forms
Possible manifestations are words, letters, figures, graphical representations, three-dimensional marks, acoustical signs, identification threads of textiles, abstract colours as well as slogans and combinations of any of the above.
The history of the trademark law can also be read as a history of the extension of the circle of registrable marks. The earlier trademark laws only considered graphical marks or combination marks consisting of word and picture. Later, word marks, whose legal protection extends to all variants and ways of writing of the registered word, got registrable. In recent time new forms, such as form marks, for instance the "Coca Cola®" bottle, sound marks (phonetic marks) like the "Migros Jingle®", abstract colour marks (the "yellow" of the Swiss Post) were added as registrable trademarks. The circle of possible mark owners was also extended. Until the 90's of the last century only a protection for the marking of goods could be attained. Today businesses providing services are eligible for trademark registration. In addition, slogans are in principle registrable as trademarks.
(By courtesy of the Swiss Federal Institute of Intellectual Property)