by the International Bureau published in May 2008
Articles published in scientific and technical journals often contain a certain number of references to earlier publications. Patent applications also very often contain (e.g., in the descriptions of the inventions) references to earlier patents or patent applications, or other industrial property rights. In the course of the procedure for obtaining a patent, patent examiners cite one or several patent documents or other documents which describe similar or closely related technical solutions to the one described in a patent application being examined, in order to illustrate the prior art.
Some industrial property offices, but not all of them, bring these cited references to the attention of the general public, by including them in a published patent document. The present Recommendation is intended to generalize the inclusion in patent documents of “reference(s) cited” during the patent examination procedure, to standardize the way in which the said references should be presented in the patent document and to recommend a preferred place, where the “reference(s) cited” should appear.
For the purposes of this Recommendation, the term “patents” includes such industrial property rights as patents for inventions, plant patents, design patents, inventors’ certificates, utility certificates, utility models, patents of addition, inventors’ certificates of addition, and utility certificates of addition.
For the purposes of this Recommendation, the expression “patent applications” or “applications for patents” includes applications for patents for inventions, plant patents, design patents, inventors’ certificates, utility certificates, utility models, patents of addition, inventors’ certificates of addition, and utility certificates of addition.
For the purposes of this Recommendation, the expression “patent documents” includes patents for inventions, plant patents, design patents, inventors’ certificates, utility certificates, utility models, patents of addition, inventors’ certificates of addition, utility certificates of addition, and published applications therefor.
Applications for patents are examined by a governmental authority or intergovernmental authority which, as a rule, is an industrial property office. A patent for invention is granted if the application complies with the formal requirements and, depending on whether and to what extent an “examination as to substance” is carried out, if the invention fulfills the substantive requirements of the respective patent law.
When patent applications are examined or search reports are established therefor, a certain number of patent documents and other documents might be cited as references to illustrate the prior art by the industrial property office (including a regional Office, and an International Searching Authority under the PCT).
References to the following Standards are of relevance to this Recommendation:
WIPO Standard ST.1:
Recommendation Concerning the Minimum Data Elements Required to Uniquely Identify a Patent Document;
WIPO Standard ST.2:
Standard Manner for Designating Calendar Dates by Using the Gregorian Calendar;
WIPO Standard ST.3:
Recommended Standard on Two‑Letter Codes for the Representation of States, Other Entities and Intergovernmental Organizations;
WIPO Standard ST.9:
Recommendation Concerning Bibliographic Data on and Relating to Patents and SPCs;
WIPO Standard ST.13:
Recommendation for the Numbering of Applications for Industrial Property Rights (IPRs);
WIPO Standard ST.16:
Recommended Standard Code for the Identification of Different Kinds of Patent Documents;
WIPO Standard ST.20:
Recommendations for the Preparation of Name Indexes to Patent Documents;
International Standard ISO 4:1997: “Information and Documentation – Rules for the abbreviation of title words and titles of publications”;
International Standard ISO 690:1987: “Documentation – Bibliographic references – Content, form and structure”;
International Standard ISO 690‑2:1997: “Information and documentation – Bibliographic references – Part 2: Electronic documents or parts thereof”;
International Standard ISO 999:1996: “Information and documentation – Guidelines for the content, organization and presentation of indexes”.
It is recommended that industrial property offices should include in their granted patents and in their published patent applications all relevant references cited in the course of a search or examination procedure.
It is recommended that the “List of references cited” be identified by INID code (56).
It is recommended that the “List of references cited” appear either
(a) on the first page of the patent document or
(b) in a search report attached to the patent document.
It is recommended that if the “List of references cited” appears in a search report attached to the patent document, (e.g., under the PCT procedure) this should be indicated on the first page of the patent document.
It is recommended that the documents in the “List of references cited” be organized in a sequence suitable to the users’ needs, this sequence being clearly illustrated in the presentation of the said list. The following is an example of a sequence of documents cited:
(a) domestic patent documents;
(b) foreign patent documents;
(c) non‑patent literature.
In search reports, however, the documents may be cited in the order of their pertinence.
Identification of any document or announcement cited, and available in paper form or in a page-oriented presentation mode (e.g., facsimile, microform, etc.) shall be made by indicating the following elements in the order in which they are listed:
(a) In the case of a patent document:
(i) the industrial property office that issued the document, by the two‑letter code (WIPO Standard ST.3);
(ii) the number of the document as given to it by the industrial property office that issued it (for Japanese patent documents, the indication of the year of the reign of the Emperor must precede the serial number of the patent document);
(iii) the kind of document, by the appropriate symbols as indicated on the document under WIPO Standard ST.16 or, if not indicated on that document, as provided in that Standard, if possible;
(v) 2the date of publication of the cited patent document (using four digits for a year designation according to the Gregorian Calendar) or, in case of a corrected patent document, the date of issuance of the corrected patent document as referred to under INID code (48) of WIPO Standard ST.9 and, if provided on the document, the supplementary correction code as referred to under INID code (15);
(vi) 1where multiple renderings of the same document are published (e.g., PDF and HTML), an indication of the location and format (e.g., PDF) of the cited document;
(vii) 1paragraph numbers, sentence numbers and line numbers to describe the specific location of the cited material within a document if they are available;
(viii) 1claim numbers, figure numbers, chemical formula numbers, mathematical formula numbers, table heading numbers, gene sequence numbers, and computer program listing numbers if available;
(ix) 1if no paragraph numbers exist, or if the paragraph is long, use page numbers, column numbers, and line numbers (if available) to describe the specific location of the cited material within a document;
(x) 1specific headings within the document structure such as Best Mode of Performing the Invention or Industrial Applicability can be indicated if page, paragraph, and line numbers are not available;
(xi) 1specific passages of the text can be indicated if the format of the document includes pagination or an equivalent internal referencing system, or by the first and last words.
The following examples illustrate the citation of a patent document according to paragraph (a), above:
Example 1: JP 10-105775 A (NCR INTERNATIONAL INC) 24 April 1998, paragraphs  to .
Example 2: DE 3744403 A1 (JOSEK, A) 1991.08.29, page 1, abstract.
Example 3: SE 504901 C2 (SWEP INTERNATIONAL AB) 1997-05-26, claim 1.
Example 4: US 5635683 A (MCDERMOTT, RM et al.) June 3, 1997, column 7, lines 21 to 40.
Example 5: ES 2156718 A1 (AGQ SL) 1 July 2001, the whole document.
Example 6: WO97/28071 A1 corrected version (GENERAL SIGNAL CORP) available 1998-05-07, page 3 lines 20‑28.
Example 7: WO 2007/077970 A1 (MEIJI DAIRIES CORP) 2007.07.12, paragraph  from “ Another aspect … assumes 30%‑60%”.
(b) In the case of a published intellectual property office document or announcement, e.g., registered industrial design, registered trademark, published pending trademark and registered copyright documents, not specifically provided for elsewhere under paragraph 12:
(i) the intellectual property office that issued the document or announcement, by the two-letter code (WIPO Standard ST.3);
(ii) the serial number of the application or registration or the number of the document or announcement as given to it by the intellectual property office that issued it;
(iii) the type of intellectual property office document or announcement (e.g., registered industrial design, trademark registration, trademark application, copyright registration, etc.);
(v) where applicable, the title of the gazette in which the application or registration was announced and the issue designation of the gazette;
(vi) the date of publication using four digits for the year designation (where year, month and day are available, the provisions of WIPO Standard ST.2 should be applied);
(vii) 1where applicable, the location of relevant passages or figures within the document or announcement;
(viii) if considered necessary, the standard identifier and the number assigned to the item, e.g., ISSN 0250-7730.
The following examples illustrate the citation of a document or announcement according to paragraph (b), above:
Example 1: WO DM/032099, Industrial Design (POWER-PACKER EUROPA B.V.) 1995‑04‑28, International Designs Bulletin February 1995, No. 2, pages 752 and 753, figures 1.1 and 1.3, ISSN 0250‑7730.
Example 2: DE M 94 01 995, Geschmacksmuster, Geschmacksmusterblatt, Heft 15, 1994.08.10, S. 3810.
Example 3: US TXu-499-733, copyright registration, ELSTON, William J, 1991.12.16.
Example 4: ES M 0279288, trademark registration (SUDNIF SA) 2001-05-16.
(c) In the case of a monograph or parts thereof, e.g., contributions to conference proceedings, etc.:
(i) the name of the author (in capital letters)3; in the case of a contribution, the name of the author of the contribution;
(ii) in the case of a contribution, the title of the contribution followed by “In:”;
(iii) the title of the monograph; in the case of a contribution, the designation of the editorship;
(iv) in the case of conference proceedings, the conference title, date, number, place (if available);
(v) the number of the edition;
(vi) 1the place of publication and the name of the publisher (where only the location of the publisher appears on the monograph, then that location shall be indicated as the place of publication; in the case of company publications, the name and postal address of the company);
(vii) the year of publication, by four digits4;
(viii) if applicable, the standard identifier and number assigned to the item, e.g., ISBN 2‑7654‑0537-9, ISSN 1045-1064. It should be noted that these numbers may differ for the same title in the print and electronic versions;
(ix) 1the location within the monograph by indicating the pages, columns, lines or paragraph numbers where the relevant passages appear, or the relevant figures of the drawings (if applicable).
The following examples illustrate the citation of a monograph (Example 1), as well as of published conference proceedings (Example 2), according to paragraph (c), above:
Example 1: WALTON, Herrmann. Microwave Quantum Theory. London: Sweet and Maxwell, 1973, Vol.2,
ISBN 5-1234-5678-9, pages 138 to 192, especially pages 146 to 148.
Example 2: SMITH et al. ‘Digital demodulator for electrical impedance imaging’. In: IEEE Engineering in Medicine & Biology Society, 11th Annual Conference. Edited by Y. Kim et al. New York: IEEE, 1989, Vol.6, p. 1744‑5.
(d) In the case of an article published in a periodical or other serial publication:
(i) the name of the author (in capital letters)3;
(ii) the title of the article (where appropriate, abbreviated or truncated) in the periodical or other serial publication;
(iii) the title of the periodical or other serial publication (abbreviations conforming to generally recognized international practice may be used; see "PCT Minimum Documentation - List of Periodicals", Part 4);
(iv) the location within the periodical or other serial publication by indicating date of issue by four digits for the year designation, issue designation, pagination of the article (where year, month and day are available, the provisions of WIPO Standard ST.2 should be applied);
(v) where applicable, the standard identifier and number assigned to the item, e.g., ISBN 2‑7654‑0537‑9, ISSN 1045‑1064. It should be noted that these numbers may differ for the same title in the printed and electronic versions;
(vi) 1where applicable, the relevant passages of the article and/or the relevant figures of the drawings.
The following example illustrates the citation of an article published in a periodical or other serial publication according to paragraph (d), above:
Example: DROP, JG. Integrated Circuit Personalization at the Module Level. IBM tech. dis. bull. October 1974, Vol.17, No.5, pages 1344 and 1345, ISSN 2345‑6789.
(e) In the case of an abstract not published together with the full text document which serves as its basis:
the identification of the document containing the abstract, the abstract and the full text document shall be made on the basis of the bibliographic data available in respect thereof.
The following examples illustrate the citation of an abstract according to paragraph (e), above:
Example 1: SHETULOV, DI. Surface Effects During Metal Fatigue. Fiz.-Him. Meh. Mater. 1971, 7(29), 7‑11 (Russ.). Columbus, OH, USA: Chemical abstracts, Vol. 75, No. 20, 15 November 1971, page 163, column 1, abstract No. 120718k.
Example 2: JP 3-2404 A (FUDO). Patent abstracts of Japan, Vol. 15, No. 105 (M‑1092), 1991.03.13 (abstract).
Example 3: SU 1374109 A (KARELIN, VI) 1988.02.15. (abstract), Soviet Patent Abstracts, Section E1, Week 8836, London: Derwent Publications Ltd., Class S, AN 88-255351.
Identification of an electronic document, e.g., retrieved from a CD‑ROM, the Internet or from an online database accessible outside the Internet, shall be made in the manner indicated in subparagraphs 12(a), (b), (c), (d) and (e), above, as far as possible and completed, as suggested in the items below.
Attention is drawn to the following items which are modeled after guidelines provided by the International Organization for Standardization’s established Standard ISO 690-2 “Information and documentation – Bibliographic references – Part 2: Electronic documents or parts thereof”. These items should be provided in the locations indicated:
(i) type of medium in square brackets [ ] after the title of the publication or the designation of the host document, e.g., [online] [CD‑ROM] [disk] [magnetic tape]. If desired, the type of publication (e.g., monograph, serial, database, electronic mail, computer program, bulletin board) may also be specified in the type of medium designator;
(ii) date when the document was retrieved from the electronic media in square brackets, following the date of publication [retrieved on 1998-03-04];
(iii) identification of the source of the document using the words “Retrieved from” and its address where applicable; this item will precede the citation of the relevant passages;
(iv) 6reference to the unique Digital Object Identifier (DOI) number, or other unique identification number, if known;
(v) if considered necessary, the standard identifier and number assigned to the item, e.g., ISBN 2‑7654‑0537‑9, ISSN 1045‑1064. It should be noted that these numbers may differ for the same title in the printed and electronic versions;
(vi) 1where multiple renderings of the same document are published (e.g., PDF and HTML), an indication of the format (e.g., paper, PDF) and the location of the cited document;
(vii) 1use paragraph numbers, sentence numbers and line numbers (if available) to describe the specific location of the cited material within an electronic document;
(viii) 1claim numbers, figure numbers, chemical formula numbers, mathematical formula numbers, table heading numbers, gene sequence numbers, and computer program listing numbers if available;
(ix) 1specific headings within the document structure such as Best Mode of Performing the Invention or Industrial Applicability can be indicated if page, paragraph, and line numbers are not available in a cited patent document in electronic format;
(x) specific passages of the text can be indicated if the format of the document includes pagination or an equivalent internal referencing system, or by their first and last words.
Office copies of an electronic document should be retained if the same document may not be available for retrieval in the future. This is especially important for sources such as the Internet and online databases.5
If an electronic document is also available in paper form or in a page-oriented presentation mode (see paragraph 12, above) it does not need to be identified as an electronic document, unless it is considered desirable or useful to do so.
The following examples illustrate citations of electronic documents:
Examples 1-4: Documents retrieved from online databases outside the Internet
Example 1: SU 1511467 A (BRYAN MECH) 1989-09-30 (abstract) World Patents Index [database online]. Derwent Publications, Ltd. [retrieved on 1998-02-24]. Retrieved from: Questel. DW9016, Accession No. 90-121923.
Example 2: DONG, XR. ‘Analysis of patients of multiple injuries with AIS-ISS and its clinical significance in the evaluation of the emergency managements’, Chung Hua Wai Ko Tsa Chih, May 1993, Vol. 31, No. 5, pages 301‑302, (abstract) Medline [online]: United States National Library of Medicine [retrieved on 24 February 1998]. Retrieved from: Dialog. Medline Accession no. 94155687, Dialog Accession No. 07736604.
Example 3: JENSEN, BP. ‘Multilayer printed circuits: production and application II’. Electronik, June-July 1976, No. 6-7, pages 8, 10,12,14,16. (abstract) INSPEC [online]. London, U.K.: Institute of Electrical Engineers [retrieved on 1998‑02‑24]. Retrieved from: STN International, USA. Accession No. 76:956632.
Example 4: JP 3002404 A (Tamura Toru) 1991‑03‑13 (abstract). [online] [retrieved on 1998‑09‑02]. Retrieved from: EPOQUE PAJ Database.
Examples 5-15: Documents retrieved from the Internet
Example 5: (Electronic patent document – not page based) – two examples
WO 2004/091307 A2 (ADVANCED BIONUTRITON CORP) 2004‑10‑28, paragraphs , ; examples 2,6.
GB 2,432,062 A (GE INSPECTION TECHNOLOGY LP) 2007.05.09, Detailed Description, third paragraph beginning ‘Referring to Figure 2’.
Example 6: (Electronically registered Intellectual Property – other than patent documents)
HU D9900111 Industrial Design Application, (HADJDÚTEJ TEJIPARI RT, DEBRECEN) 2007‑07‑19, [database online], [retrieved on 1999‑10‑26] Retrieved from the Industrial Design Database of the Hungarian Patent Office using Internet
Example 7: (Entire Work – Book or Report)
WALLACE, S, and BAGHERZADEH, N. Multiple Branch and Block Prediction. Third International Symposium on High-Performance Computer Architecture [online], February 1997 [retrieved on 2007‑07‑18]. Retrieved from the Internet: <URL: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=569645&isnumber=12370> <DOI: 10.1109/HPCA.1997.569645>.
National Research Council, Board on Agriculture, Committee on Animal Nutrition, Subcommittee on Beef Cattle Nutrition. Nutrient Requirements of Beef Cattle [online]. 7th revised edition. Washington, DC: National Academy Press, 1996 [retrieved on 2007‑07‑19]. Retrieved from the Internet:
<URL: http://books.nap.edu/openbook.php?record_id=9791&page=24> Chapter 3, page 24, table 3‑1, ISBN-10: 0‑309‑06934‑3.
Example 9: (Electronic Serial – articles or other contributions)
AJTAI, Miklos. Generating Hard Instances of Lattice Problems. Electronic Colloquium on Computational Complexity, Report TR96-007 [serial online], [retrieved on 1996‑01‑30]. Retrieved from the Internet:
Example 10: OWEN, RW et al. Olive-oil consumption and health: the possible role of antioxidants. Lancet Oncology, Vol 1, No. 2, 1 October 2000 , pp. 107‑112 [online], [retrieved on 2007‑07‑18]. Retrieved from the Internet <URL: http://www.ingentaconnect.com/content/els/14702045/2000/00000001/00000002/art0001> <DOI: 10.1016/S1470‑2045(00)00015‑2>
Example 11: (Electronic bulletin boards, message systems, and discussion lists – Entire System)
BIOMET‑L (A forum for the Bureau of Biometrics of New York) [bulletin board online]. Albany (NY): Bureau of Biometrics, New York State Health Department, July, 1990 [retrieved 1998‑02‑24]. Retrieved from the Internet: <email@example.com>, message: subscribe BIOMET‑L your real name.
Example 12: (Electronic bulletin boards, message systems, and discussion lists – Contributions)
PARKER, Elliott. ‘Re: citing electronic journals’. In PACS-L (Public Access Computer Systems Forum) [online]. Houston (TX): University of Houston Libraries, November 24, 1989; 13:29:35 CST [retrieved on 1998‑02‑24]. Retrieved from the Internet:
Example 13: (Electronic mail)
‘Plumb design of a visual thesaurus’. The Scout Report [online]. 1998, vol. 5 no. 3 [retrieved on 1998.05.18]. Retrieved from Internet electronic mail: <firstname.lastname@example.org>, subscribe message: info scout-report. Retrieved from the Internet: <URL: http://scout.wisc.edu/Reports/ScoutReport/1998/scout-980515.html#13> ISSN: 1092-3861.
Example 14: (Product Manual/Catalogue or other information obtained from a Web-site)
Corebuilder 3500 Layer 3 High-function Switch. Datasheet [online]. 3Com Corporation, 1997 [retrieved on 1998‑02‑24]. Retrieved from the Internet:
Examples 15 and 16: Documents retrieved from CD-ROM products
Example 15: JP 08000085 A (TORAY IND INC), (abstract), 1996-05-31. In: Patent Abstracts of Japan [CD‑ROM].
Example 16: HAYASHIDA, O et al. Specific molecular recognition by chiral cage-type cyclophanes having leucine, valine, and alanine residues. Tetrahedron 1955, Vol. 51 (31), p. 8423‑36. In: Chemical Abstracts [CD-ROM]. CAS Abstract 124:9350.
It is recommended that any document (reference) referred to in paragraph 7, above, and cited in the search report should be indicated by the following letters or a sign to be placed next to the citation of the said document (reference):
(a) Categories indicating cited documents (references) of particular relevance:
Category “X”: The claimed invention cannot be considered novel or cannot be considered to involve an inventive step when the document is taken alone;
Category “Y”: The claimed invention cannot be considered to involve an inventive step when the document is combined with one or more other such documents, such combination being obvious to a person skilled in the art.
(b) Categories indicating cited documents (references) of other relevant prior art:
Category “A”: Document defining the general state of the art which is not considered to be of particular relevance;
Category “D”: Document cited by the applicant in the application and which document (reference) was referred to in the course of the search procedure. Code “D” should always be accompanied by one of the categories indicating the relevance of the cited document;
Category “E”: Earlier patent document as defined in Rule 33.1(c) of the Regulations under the PCT, but published on or after the international filing date;
Category “L”: Document which may throw doubts on priority claim(s) or which is cited to establish the publication date of another citation or other special reason (the reason for citing the document shall be given);
Category “O”: Document referring to an oral disclosure, use, exhibition or other means;
Category “P”: Document published prior to the filing date (in the case of the PCT, the international filing date) but later than the priority date claimed in the application. Code “P” should always be accompanied by one of the categories “X”, “Y” or “A”;
Category “T”: Later document published after the filing date (in the case of the PCT, the international filing date) or priority date and not in conflict with the application but cited to understand the principle or theory underlying the invention;
Category “&”: Document being a member of the same patent family or document whose contents have not been verified by the search examiner but are believed to be substantially identical to those of another document which the search examiner has inspected.
The list of cited documents (references) given in the search report should indicate, conforming to the generally recognized practice of the International Searching Authorities under the Patent Cooperation Treaty, the respective claim(s) of the patent application to which the citation is considered to be relevant.
The category codes referred to in paragraph 14, above, are intended primarily for use in the context of search reports accompanying published patent applications. However, if industrial property offices wish to indicate the relevance of cited documents (references) listed on the first page of a published patent application, they should print the category codes in parentheses, immediately after each citation.
Note: Further detailed information on definitions of terms used in this Standard or on the inclusion of references cited can be found in International Standard ISO 690:1987, “Documentation – Bibliographic References – Content, Form and Structure”. Guidance for the abbreviation of titles of articles can be obtained through International Standard ISO 4:1997, “Information and Documentation – Rules for the Abbreviation of Title Words and Titles of Publications”.
[End of Standard]
2 The elements of item (v), having relevance to a corrected patent document, should be indicated together with the other data referred to under subparagraph 13(a)(i) to (iii).
4 When the year of publication coincides with the year of the application or of the priority claim, the month and, if necessary, the day of publication of a monograph or parts thereof should be indicated in accordance with the provisions set out in WIPO Standard ST.2.
5 It should be noted that while an Internet address citation resulting from a search by a search engine may no longer be an active (i.e., usable) Internet address (e.g., Example 8), it may contain information which could be of use in locating the cited document or web page. For example, the home page where the document was found or the contents of the search statement may be located within the Internet address and can provide valuable information especially when considered along with the other information contained in the citation (e.g., title, author, publication date, standard identifier, etc.). Queries to the Webmaster or other staff of the relevant Internet home page may also be helpful.
6 The Digital Object Identifier (DOI) is a system for identifying content objects in the digital environment. DOIs are names assigned to any entity, such as a scientific article, for use on digital networks. DOIs are used to provide current information, including where they can be found on the Internet. Information about a digital object may change over time, including where to find it, but the DOI number will not change. Refer to http://www.doi.org/index.html.