A term that refers to the focusing of a company or inventor’s patenting efforts so as to establish patent thickets. It is usually advisable to supplement a pioneer patent with a number of CIPs on evolutions and incremental inventions so as to ensure the inventor or company’s work cannot be easily designed around. One advantage of clustering patents is that it increases the likelihood that a company will obtain blocking patents, which from a defensive perspective, may result in cross licenses or sleeping dog licenses.