It is possible that during the processing of a patent term extension, the patent owner becomes aware of situations where the filing of a terminal disclaimer might be necessary or desired. For example, if patent infringement litigation has commenced and the accused infringer advances that the patent is invalid on the basis of non-statutory obviousness type double patenting, then the patent owner might choose to file a terminal disclaimer to preempt the defense if the patent that is the basis for the non-statutory obviousness type double patenting has not expired. Boehringer Ingelheim Int’l GmbH v. Barr Laboratories Inc., 592 F.3d 1340, 93 USPQ2d 1417, 1422-23 (Fed. Cir. 2010). When a terminal disclaimer is filed for a patent during the processing of an application for patent term extension, any required updates to information already of record should be made pursuant to 37 CFR 1.765. For example, if the calculation of term changes because the patent’s expiration date changes, then an updated calculation of the term should be submitted for the application for patent term extension via the Office’s Electronic Filing System. Patent owners can use the USPTO terminal disclaimer forms (e.g., forms PTO/SB/25a or PTO/SB/26a) available at www.uspto.gov. Alternatively, patent owners can draft and file a self-prepared terminal disclaimer that meets the requirements of 37 CFR 1.321. See MPEP § 1490.