3. IPC classification of the application 

The IPC classification of a patent application is assigned by the search division.

The IPC classification identifies all features relevant to the technical subject-matter of the claimed invention (or of each of the claimed inventions if there is more than one) as precisely and comprehensively as possible under the IPC scheme.

The IPC classification consists of "invention information" symbols and "additional information" symbols (the latter include IPC indexing codes) which are assigned according to the IPC rules set out in the "Guide to the IPC". If more than one symbol has to be assigned for the invention itself, the symbol which, in the search division's opinion, best identifies it ‒ or, if that is not straightforward, the one identifying it for which most information is given ‒ is indicated first. The IPC classification should preferably be assigned after the search division has studied the content of the application to decide how to carry out the search. However, if the application is due to be published before the search report is drawn up, it will have to study it in enough detail to decide on the IPC classification at this earlier stage (see B‑X, 5).

The IPC classification relates to what is disclosed in the published application, i.e. the application as filed, and so is determined without taking into consideration what the application could potentially contain if it is later amended. If, however, the search division's understanding of the invention, or of the content of the application as filed, changes significantly during the search (e.g. as a result of prior art found or because obscure points have been clarified) and the preparations for publication have not yet been completed, it will amend the classification accordingly.