c) Evidence of common general knowledge 

Belated submissions may be taken into account as evidence of alleged common general knowledge, where such knowledge has been disputed (T 106/97, T 1076/00, see also T 1464/14).

In T 85/93 (OJ 1998, 183) the board pointed out that evidence of common general knowledge, like any other evidence in support of an opponent's submissions, should be filed at an early stage in the proceedings before the opposition division, and might be rejected as inadmissible at the board's discretion if filed for the first time during appeal proceedings.

In T 274/99 the board considered the late-filed textbook under Art. 114(1) EPC 1973 – although late-filed documents, including those that prove common general knowledge, could be disregarded under the boards' case law – because it provided a better understanding of the state of the art, it was obviously relevant, its submission could be seen as reasonable as far as the respondent was concerned, and its consideration did not delay the proceedings in any way.