In its decisions G 1/03 and G 2/03 (OJ 2004, 413 and 448) the Enlarged Board of Appeal used the term "disclaimer" as meaning an amendment to a claim resulting in the incorporation therein of a "negative" technical feature, typically excluding specific embodiments or areas from a general feature. The requirements of Art. 84 EPC apply to a disclaimer as to any other feature of a patent claim (T 2130/11; see also T 1487/09).
Disclaimers play an important role in the drafting of claims and amendments. The principles concerning the allowability of disclaimers are set out in Chapter II.E.1.5.3 d) "Drafting of disclaimers – clarity".