A situation that arises where a patent applicant files two patents whose claims would cover the same invention. This particularly can occur with Continuations-in-Part and in the U.S. is usually resolved by filing a Terminal Disclaimer giving up any excess term the second patent would enjoy over the first as well as from time-to-time agreeing to that the overlapping patents be kept in common ownership. In all other instances, it would usually lead to invalidity of the second patent.