The examining division has raised an objection under Article 123(2) indicating that a certain feature introduced into the claims extends the subject-matter of the application as filed.
Unless the applicant is able to demonstrate to the satisfaction of the examining division that the application as filed disclosed this feature directly and unambiguously, the examining division will normally not admit under Rule 137(3) any further set of claims containing the feature in question.
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/h_ii_2_3_1_2.htm
Date retrieved: 17 May 2021