Under Art. 123(2) it is impermissible to add to a European application matter present only in the priority document for that application (see T 260/85), unless this is done under the provisions of Rule 56(3) (H‑IV, 2.3.2). For correction of errors, see H‑VI, 4.
In order to verify that the limitation introduced into the claim(s) meets the requirements of Art. 123(2), the application documents as filed are the ones to be considered. In rare cases where the patent to be limited is of an older date, it may happen that the original file is destroyed, with the result that the original application documents as filed are no longer available (see Rule 147 and the Decision of the President of the EPO dated 12 July 2007, Special edition No. 3, OJ EPO 2007, J.1). Examination of Art. 123(2) has then to be based on the available published application instead of the original application documents, on the assumption that it is identical in content to the application as filed.