Claim term is given meaning other than its ordinary and customary meaning only in limited situations, and term must be assigned its ordinary meaning if written description and prosecution history are ambiguous as to whether patentee used term in manner inconsistent with such meaning. Claim term will not receive its ordinary and customary meaning only in limited situations. Those situations include: where the patentee has acted as his own lexicographer and clearly provided an alternate definition for the term; where the intrinsic evidence shows that the patentee distinguished invention from a prior art reference, expressly disclaimed subject matter, or highlighted a particular feature as important to the invention; or, where the term chosen makes the scope of the claim so unclear as to require resort to the intrinsic evidence for meaning. (W.E. Hall Co. v. Atlanta Corrugating LLC, 71 USPQ2d 1135, CA FC, 6/7/04).