The systematically accessible search documentation includes the relevant articles from the list of periodicals belonging to the minimum documentation under the PCT as established by the competent WIPO body and from other periodicals where deemed useful by the search division. In principle, copies of the articles selected as relevant for search purposes are added to the EPO search databases with a fictitious country code "XP", scanned for inclusion in the electronic "BNS" collection and included in the manual search files, where appropriate.

The EPO also subscribes to many further periodicals including abstract journals. Furthermore, records of conference proceedings, reports, books, standards, etc. covering the three official languages of the EPO and the various technically important geographical areas are obtained. Individual items are selected for inclusion in the online documentation in so far as they constitute useful additions to the state of the art.