All documents cited in the search report must be identified unambiguously by indicating the necessary bibliographic elements. All citations in the search report normally comply with WIPO Standard ST.14 (Recommendation for the inclusion of references cited in patent documents), WIPO Standard ST.3 (Two-letter codes) and ST.16 (Standard code for identification of different kinds of patent documents). This does not exclude deviations in those special cases where strict adherence, whilst not necessary for the clear and easy identification of a document, would require considerable extra cost and effort.
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/b_x_9_1_1.htm
Date retrieved: 17 May 2021