Use Of Nofollow On An Internal Link

Nofollow is sometimes used in internal linking of website to stop the pagerank flow to unimportant links. One can add nofollow for the internal pages such as Contact us, privacy policy, company profile pages which tells search engines that the links may be a non relevant or unimportant. In such case the page rank won't be transferred to such internal pages. In other words to stop link juice from flowing to minor pages like Terms and Conditions or privacy policy.