The opinion
MILLER, Judge
(concurring).
I agree that the board violated the basic rule that third party (i. e., stranger to the proceeding) inventorship is not ancillary to priority and must, therefore, be reversed.
This court, in Goodrich v. Harmsen, 442 F.2d 377 , 58 CCPA 1144 (1971), decided that the third party in a three-way interference suit is not a “stranger” for purposes of the rule, “third party inven-torship is not ancillary to priority.” In that case the court allowed Goodrich to argue the issue of derivation by Lokey (also a party to the interference) from Harmsen, stating:
It is unquestionably true that either party to a two-party interference has standing to assert that the other derived the invention in issue from it, 1 Revise & Caesar, Interference Law and Practice § 113 (1940), and we see no reason in law or logic why any party to an interference involving three or more parties should not be able to show that a second party derived the invention from a third party, if proof of that fact would advance the prover’s case. Certainly that result will lead to an overall saving of administrative and judicial effort, and it does not seem to be inconsistent with the narrow scope of present interference practice.
Because of this statement, it has been suggested that the court “may to some extent have weakened the foundation” of the basic rule that third party inven-torship is not ancillary to priority and that there is “compelling logic” in favor of proof of derivation from strangers to an interference. Pat.L.Persp. § C.2[4] (1971 Dev.).
One reason for not allowing proof of derivation from a stranger to an interference is the complexity it might impose on interference proceedings. This was described in Foster v. Antisdel, 14 App.D.C. 552 , 1899 CD 413 (1899):
Indeed, if the practice obtained of allowing the claims and pretensions of any and all persons, though not parties to the proceeding, to be set up as means of defeating the priority of claim of one of the parties to the proceeding, it would be very difficult, if not almost impossible, in many cases, to try the issue of interference as between the immediate parties to it. Such practice would open the door to all sorts of collusions, and perjury would be the recourse of many who failed to support their claims by legitimate evidence.
The long-standing refusal of courts to consider derivation from a stranger to the interference is another reason. Moreover, it is arguable that, when Congress enacted 35 U.S.C. § 102 (g), it adopted the rule promulgated by prior court decisions that proof of derivation from a stranger to an interference is not ancillary to priority. 1
A further reason for not permitting proof of derivation from a stranger to an interference is that an interference proceeding is provided only for the purpose of determining priority between the parties. Cooper v. Hubbell, 53 F.2d 1072, 1078 , 19 CCPA 790, 801 (1931); see Holister v. Maynard, 129 F.2d 877 , 29 CCPA 1249 (1942). Even though one who derived the invention from a stranger to the interference might be “awarded”'priority, the Patent and Trademark Office (PTO) can reject pertinent claims of his *1174 application 2 in subsequent ex parte prosecution on the ground that he “did not himself invent the subject matter sought to be patented.” 35 U.S.C. § 102 (f). Under Rule 259, 37 CFR 1.259, the Board of Patent Interferences may, before or concurrently with its decision on priority, direct the attention of the Commissioner to facts which bar the grant of a patent to any of the parties in the interference. ■The Commissioner may suspend the interference and remand the case to the primary examiner for his consideration of such information. Therefore, Rule 259 provides a means for accomplishing the result attempted by the board in this case, without violating the rule that third party inventorship is not ancillary to priority.
There appears to be only one circumstance which, in the absence of Congressional action, warrants what might be considered an exception to the rule. This is where there is an issue of fraud which involves third party derivation. It is contrary to public policy to award priority to the guilty party, and this court has said that the question of fraud is ancillary to priority. Langer v. Kaufman, 465 F.2d 915, 921 , 59 CCPA 1261, 1267 (1972).
. With respect to 35 U.S.C. § 102 (g), the Congressional committee reports state:
This paragraph retains the present rules of law governing the determination of priority of invention.
S.Rep.No.1979, 82d Cong., 2d Sess. 18 (1952), U.S.Code Cong. & Admin.News, pp. 2394, 2410; H.R.Rep.No. 1923, 82d Cong., 2d Sess. 18 (1952). See also P. J. Federico, Commentary on the New Patent Act, 35 U.S.C.A. p. 19, where the author states that 35 U.S.C. § 102 (g) “retains the rules of law governing the determination of priority of invention developed by decisions.” (Emphasis supplied.)
. Of course, where the deriver is a patentee, he would not be subjected to further PTO ex parte prosecution in the absence of a subsequent reissue application. However, his patent would be vulnerable in an infringement or declaratory judgment action.