In pejorative usage, a patent troll is a person or company that attempts to enforce patent rights against accused infringers far beyond the patent's actual value or contribution to the prior art. Patent trolls often do not manufacture products or supply services based upon the patents in question. However, some entities which do not practice their asserted patent may not be considered "patent trolls" when they license their patented technologies on reasonable terms in advance. Other related terms include patent holding company (PHC), patent assertion entity (PAE), and non-practicing entity (NPE), which may or may not be considered a "patent troll" depending on the position they are taking and the pe****tion of that position by the public.