User blog comment:Semanticdrifter/Understanding Trademark/@comment-124.149.45.178-20130711002827/@comment-11733175-20130711162057

Even things like Coca-cola bottle are trademarks. If it can be proven that it is a recognisable representation of a company, I think anything can. For example in '77 the coca-cola bottle (with words) was registered a trademark of the company and in '78 the bottle without the words was registeredsource.

In japan, an extension to the existing trademark laws allowed 3 dimensional designs to be registered. In 2003, Coca-cola applied for this, but it was later rejected for not being recognisable enough. In 2008 this was overturnedsource. I believe there was a similar case in Britain from what I remember of a lecture from someone in the patent office, but they may have been referring to the japanese case.