By Charles L. Gholz and Kenneth D. Wilcox 2, 3
According to 37 CFR 41.202(a):
An applicant, including a reissue applicant, may suggest an interference with another application or a patent. The suggestion must:
(4) Explain in detail why the applicant will prevail on priority...
However, that rule and its predecessors have never been interpreted as requiring the applicant to explain (or at least preliminarily prove) that it will actually “prevail on priority” after the opponent’s priority evidence has been considered. What it means is that the suggestion of interference must make a prima facie showing that the applicant can at least beat the opponent’s filing date or presumptive effective filing date for the target claims(s) if the opponent submits no evidence attacking the applicant’s prima facie showing.4
In practice, the examiner to whom the suggestion is submitted can assert that the target claim(s) is or are entitled to the benefit of a filing date earlier than the filing date that the suggestion alleges that it is or they are entitled to and earlier than the invention date(s) evidenced by the applicant’s showing. If so, that issue can be thrashed out (preliminarily) ex parte (including on appeal). If and only if the applicant is ultim...