What cannot be patented (patentable subject matter)?

Abstract ideas, mathematical formulas, physical law of nature, natural phenomena, naturally-occurring products, and printed matter are all considered non-patentable subject matter.

In some justifications, methods of medical treatment of humans is also excluded from patentable subject matter.

The patentability of computer implemented inventions is a hot and evolving topic in many jurisdictions. Generally, assessment typically balances on whether the claimed invention is considered abstract or technical in nature.