The search does not normally take into consideration documents published after the filing date of the application. However, some extension is necessary for specific purposes, as is apparent from VI, 2 to 4, and VI, 5.3.

Certain other situations may occur in which a document published after the filing date is relevant; examples are a later document containing the principle or theory underlying the invention, which may be useful for a better understanding of the invention, or a later document showing that the reasoning or the facts underlying the invention are incorrect (see Art. 84 and C-III, 6.3). The search should not be extended for this purpose, but documents of this nature known to the examiner could be selected for citation in the report (see X, 9.2(v)).