3.1 Common general knowledge of the skilled person 

Common general knowledge can come from various sources and does not necessarily depend on the publication of a specific document on a specific date. An assertion that something is common general knowledge need only be backed by documentary evidence (e.g. a textbook) if this is contested (see G‑IV, 2 G‑IV, 1).

A single publication (e.g. a patent document, but also the content of a technical journal) cannot normally be considered common general knowledge (see T 475/88). In special cases, articles in technical journals can be representative of common general knowledge (see T 595/90), in particular where they provide a broad review or survey of a topic (see T 309/88). For the skilled person addressing the problem of bringing together certain starting materials, the conclusions of research on these materials carried out by only a very few manufacturers form part of the relevant general technical knowledge, even if the studies in question have only been published in technical journals (see T 676/94). Another exception is that the common general knowledge can also be the information contained in patent specifications or scientific publications if the invention is in a field of research which is so new that the relevant technical knowledge is not yet available from textbooks (see T 51/87).

Basic textbooks and monographs can be considered to represent common general knowledge (see T 171/84). If they refer the reader to other articles dealing with specific problems, these articles too may be counted as part of this knowledge (see T 206/83). Information does not become common general knowledge because it has been published in a particular textbook, reference work, etc.; on the contrary, it appears in books of this kind because it is already common general knowledge (see T 766/91). This means that the information in such a publication must have already become part of common general knowledge some time before the date of publication.