But such cases are rare.In re Yardley, 493 F.2d 1389, 181 USPQ 331 (CCPA 1974). 37 CFR 202.
In 1974, the Court of Customs and Patent Appeals finally did address the doctrine head-on, and found it to be unsupported by the statutes. In re Yardley, 493 F.2d 1389 (C.C.P.A. 1974). Following Yardley, PTO reversed its policy on the election of protection doctrine.