A subsequent application for the same subject-matter and filed in or for the same state or member of the WTO is considered as the "first application" for priority purposes if, at the date this subsequent application was filed, the still earlier application had been withdrawn, abandoned or refused, without being open to public inspection and without leaving any rights outstanding, and had not served as a basis for claiming priority. The EPO will not consider this question unless there is evidence of the existence of a still earlier application as, for example, in the case of a United States continuation-in-part application. Where it is clear that a still earlier application for the same subject-matter exists, and where the priority right is important because of intervening prior art (see F‑VI, 2.1), the applicant is required to establish by evidence from an appropriate authority (normally a national patent office) that there were no rights outstanding in the still earlier application in respect of the subject-matter of the application being examined.[Art. 87(4); ]

Examples of applications that cannot be recognised as a "first application" within the meaning of Art. 87(4) are:

In the case of US con or cip applications, the first sentence of the description reads as follows: "This application is a continuation in part (continuation) of Serial Number .... filed .....". The following information is found on the title page under the heading "CONTINUING DATA******": "VERIFIED THIS APPLICATION IS A CIP (or CON) OF ........" A form headed "Declaration for Patent Application" must also be attached to the end of the application (in this case the priority document), listing earlier foreign or US applications under the heading "foreign priority benefits under Title 35, United States Code, 119" or "benefit under Title 35, U.S.C., 120 of any United States application(s)".

Applications may be filed by reference to a previously filed application (see A‑II, 4.1.3.1). If no priority is claimed from this previously filed application, the filing by reference itself does not generate outstanding rights according to Art. 87(4).[Rule 40(1)(c); ]

For example, in the case of national applications GB1 (filed on 1 February 2002, without claiming priority) and GB2 (filed on 2 January 2008, without claiming priority), pertaining to the same subject-matter, a European application EP1 (filed on 2 January 2009) claims priority of GB2 but refers to GB1 for its content according to Rule 40(1)(c). If GB1 is withdrawn, abandoned or refused, without being open to public inspection and without having served as a basis for claiming a right of priority, the mere reference to it under Rule 40(1)(c) does not amount to an outstanding right within the meaning of Art. 87(4). Consequently, in this case the priority claim to GB2 has to be considered valid for EP1.