Fellowship of the Institute of Physics (FInstP) is "the highest level of membership attainable" by physicists who are members of the Institute of Physics (IoP), "for those with a degree in physics or related subject (or equivalent knowledge gained in the workplace) and who have made a significant impact on their sector"; it is for "distinguished physicists in recognition of their accomplishments". Honorary Fellowship (HonFInstP) is for "exceptional individuals" who can be nominated in recognition of having "contributed to physics generally or to the work of the IOP", working in fields including business, education, research, and policy relating to physics. The Institute's bye-laws limit the number of fellows in this category to being not more than 100 living Honorary Fellows at any one time. Source: Wikipedia (en)