The idea-expression dichotomy or divide is embodied in Section 102(b) of the United States copyright code. It states:

(b) In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work.

I often get calls from potential clients who as me if their “idea” can be protected by copyright and I have to explain to them that unless the idea can be embodied in a patent or used in commerce as a trademark that it is not possible through copyright law to protect such ideas.

This division between ideas and their expression also means that historical fact and actualities cannot be protected by copyright when they are publicly available, so the so-called “newsworthy event” exception to copyright law also applies to information in its purest form and in this way one could argue that a open source copyright license for an online resources such as Wikipedia is unnecessary if the articles are purely informational, and thus, unprotected by copyright as being straightforward expressions of ideas. One might even argue that the appearance of Wikipedia dilutes copyright protection for any source of factual information to a degree.