The official classification of the European patent application is performed by the examiner as described above in B‑V, 1. Preferably, this should be done when he has studied the content of the application in order to carry out the search. However, if publication of the application is due before the search report is drawn up, it is necessary for the examiner to study the application sufficiently to determine the official classification at this earlier stage (see B‑X, 5).
If the official classification of the application is in more than one sub-class, or more than one main ("00") group within a sub-class, then all such classifications should be assigned. The classification of the invention as claimed should be distinguished from any additional classification and/or indexing code. In addition, where it is necessary to assign more than one symbol for the invention itself, the symbol which in the examiner's opinion most adequately identifies it, or, when this presents difficulties, the symbol which identifies the invention for which most information is given, should be indicated first, e.g. in order to facilitate subsequent allocation of the applications.
The classification should be determined without taking into consideration the probable content of the application after any amendment, since this classification should relate to the disclosure in the published application, i.e. the application as filed. If, however, the examiner's understanding of the invention, or of the content of the application as filed, alters significantly as a result of the search (e.g. as a result of prior art found or because of clarification of apparent obscurities), he should amend the classification accordingly, if the preparations for publication have not at that stage been completed.