Next the examiner should start the search process by formulating a search strategy, i.e. a plan consisting of a series of search statements expressing the subject of the search, resulting in sections of the documentation to be consulted for the search. In its initial phase, a search strategy will contain one or more combinations of the basic components mentioned in III, 2.2. The search process should be interactive and iterative in the sense that the examiner should reformulate his initial search statement(s) according to the usefulness of the information retrieved (see III, 1.1; IV, 2.4 and IV, 2.6). When using classification units, the examiner should select the classification units to be consulted for the search, both in all directly relevant fields and in analogous fields. The selection of the classification units in related fields should be limited to:

When the examiner is in doubt about the appropriate fields in which to conduct his search, he may request advice from the appropriate directorate of Principal Directorate Tools.

Usually various search strategies are possible, and the examiner should exercise his judgement, based on his experience and knowledge of the available search tools, to select the search strategy most appropriate to the case in hand. He should give precedence to search strategies yielding sections of the documentation in which the probability of finding relevant documents is highest. Usually the main technical field of the application will be given precedence, starting with the basic components (see III, 2.2) most relevant to the specific example(s) and preferred embodiments of the claimed invention.