Where the facility provided for by Art. 14(2) has been used and the question arises as to whether a particular amendment proposed by the applicant or proprietor extends the content of the application or patent beyond the content of the application as filed and thus offends against Art. 123(2), the EPO should normally assume, in the absence of proof to the contrary, that the original translation into English, French or German is in conformity with the text in the original language, say Dutch. However, it is the original text which constitutes the basis for determining such a question. Similarly, it is the original text which determines the content of the application as filed for the purposes of Art. 54(3) (see C-IV, 6.1). An erroneous translation from Dutch or one of the other languages covered by Art. 14(2) may be brought into conformity with the original language at any time during proceedings before the EPO, i.e. during pre-grant proceedings and also during opposition proceedings. But during opposition proceedings any amendment to bring the translation into conformity must not be allowed if it offends against Art. 123(3), that is if it is an amendment of the claims of the patent which extends the protection conferred.