Works which are not original, or which are not tangibly fixed, are not protected. The work need only display a modicum of originality, but original authorship must be present. An example of a work which is not protected due to lack of originality is the white pages of a phone book (see Feist v. Rural, 499 U.S. 340 (1991)).

The law identifies several classes of material which are not subject to copyright protection:

• Ideas
• Procedures, processes, systems, and methods of operation,
• Concepts and principles
• Discoveries

Since ideas are not subject to copyright, expressions of ideas may not be subject to copyright if (as in the case of most recipes) if the expression is essentially the only way to express the idea, called the merger doctrine.

In addition, “sweat of the brow” is not protected by copyright. Intensive labor expended in creation of a work is not, in itself, sufficient to earn copyright protection (Feist).