| 01 | Dewey | Dewey Decimal Classification | 0 | |
| 02 | Abridged Dewey | | 0 | |
| 03 | LC classification | US Library of Congress classification | 0 | |
| 04 | LC subject heading | US Library of Congress subject heading | 0 | |
| 05 | NLM classification | US National Library of Medicine medical classification | 9 | |
| 06 | MeSH heading | US National Library of Medicine Medical subject heading | 9 | |
| 07 | NAL subject heading | US National Agricultural Library subject heading | 9 | |
| 08 | AAT | Getty Art and Architecture Thesaurus heading | 9 | |
| 09 | UDC | Universal Decimal Classification | 0 | |
| 10 | BISAC Subject Heading | BISAC Subject Headings are used in the North American market to categorize books based on topical content. They serve as a guideline for shelving books in physical stores and browsing books in online stores. See https://www.bisg.org/complete-bisac-subject-headings-list | 0 | 60 |
| 11 | BISAC Regional theme | A geographical qualifier used with a BISAC subject category | 5 | |
| 12 | BIC subject category | For all BIC subject codes and qualifiers, see https://bic.org.uk/resources/BIC-Standard-Subject-Categories/ | 0 | 61 |
| 13 | BIC geographical qualifier | | 0 | |
| 14 | BIC language qualifier (language as subject) | | 0 | |
| 15 | BIC time period qualifier | | 0 | |
| 16 | BIC educational purpose qualifier | | 0 | |
| 17 | BIC reading level and special interest qualifier | | 6 | |
| 18 | DDC-Sachgruppen der Deutschen Nationalbibliografie | Used for German National Bibliography since 2004 (100 subjects). Is different from value 30. See http://www.dnb.de/service/pdf/ddc_wv_aktuell.pdf (in German) or http://www.dnb.de/eng/service/pdf/ddc_wv_aktuell_eng.pdf (English) | 9 | |
| 19 | LC fiction genre heading | | 0 | |
| 20 | Keywords | For indexing and search purposes, not normally intended for display. Where multiple keywords or keyword phrases are sent, this should be in a single instance of the <SubjectHeadingText> element, and it is recommended that they should be separated by semi-colons (this is consistent with Library of Congress preferred practice) | 0 | 34 |
| 21 | BIC children’s book marketing category | See PA/BIC CBMC guidelines at https://bic.org.uk/resources/childrens-books-marketing-classifications/ | 0 | 61 |
| 22 | BISAC Merchandising Theme | BISAC Merchandising Themes are used in addition to BISAC Subject Headings to denote an audience to which a work may be of particular appeal, a time of year or event for which a work may be especially appropriate, or to further describe fictional works that have been subject-coded by genre | 0 | |
| 23 | Publisher’s own category code | | 0 | |
| 24 | Proprietary subject scheme | As specified in <SubjectSchemeName> | 0 | |
| 25 | Tabla de materias ISBN | Latin America | 0 | |
| 26 | Warengruppen-Systematik des deutschen Buchhandels | See https://vlb.de/assets/images/wgsneuversion2_0.pdf (in German) | 0 | 28 |
| 27 | SWD | Schlagwortnormdatei – Subject Headings Authority File in the German-speaking countries. See http://www.dnb.de/standardisierung/normdateien/swd.htm (in German) and http://www.dnb.de/eng/standardisierung/normdateien/swd.htm (English). Deprecated in favor of the GND | 0 | 18 |
| 28 | Thèmes Electre | Subject classification used by Electre (France) | 0 | |
| 29 | CLIL Classification thématique | France. A four-digit number, see https://clil.centprod.com/listeActive.html (in French) | 0 | 53 |
| 30 | DNB-Sachgruppen | Deutsche Bibliothek subject groups. Used for German National Bibliography until 2003 (65 subjects). Is different from value 18. See http://www.dnb.de/service/pdf/ddc_wv_alt_neu.pdf (in German) | 1 | 9 |
| 31 | NUGI | Nederlandse Uniforme Genre-Indeling (former Dutch book trade classification) | 1 | |
| 32 | NUR | Nederlandstalige Uniforme Rubrieksindeling (Dutch book trade classification, from 2002), see http://www.boek.nl/nur (in Dutch) | 1 | |
| 33 | ECPA Christian Book Category | Former ECPA Christian Product Category Book Codes, consisting of up to three x 3-letter blocks, for Super Category, Primary Category and Sub-Category, previously at http://www.ecpa.org/ECPA/cbacategories.xls. No longer maintained by the ECPA. Deprecated | 1 | 60 |
| 34 | SISO | Schema Indeling Systematische Catalogus Openbare Bibliotheken (Dutch library classification) | 1 | |
| 35 | Korean Decimal Classification (KDC) | A modified Dewey Decimal Classification used in the Republic of Korea | 1 | |
| 36 | DDC Deutsch 22 | German Translation of Dewey Decimal Classification 22. Also known as DDC 22 ger. See http://www.ddc-deutsch.de/produkte/uebersichten/ | 2 | 9 |
| 37 | Bokgrupper | Norwegian book trade product categories (Bokgrupper) administered by the Norwegian Publishers Association (http://www.forleggerforeningen.no/) | 5 | 28 |
| 38 | Varegrupper | Norwegian bookselling subject categories (Bokhandelens varegrupper) administered by the Norwegian Booksellers Association (http://bokhandlerforeningen.no/) | 5 | 28 |
| 39 | Læreplaner-KL06 | Norwegian school curriculum version. Deprecated | 6 | 53 |
| 40 | Nippon Decimal Classification | Japanese subject classification scheme | 5 | |
| 41 | BSQ | BookSelling Qualifier: Russian book trade classification | 5 | |
| 42 | ANELE Materias | Spain: subject coding scheme of the Asociación Nacional de Editores de Libros y Material de Enseñanza | 5 | |
| 43 | Utdanningsprogram | Codes for Norwegian ‘utdanningsprogram’ used in secondary education. See: http://www.udir.no/. (Formerly labelled ‘Skolefag’) | 6 | 28 |
| 44 | Programområde | Codes for Norwegian ‘programområde’ used in secondary education. See http://www.udir.no/. (Formerly labelled ‘Videregående’ or ‘Programfag’) | 6 | 32 |
| 45 | Undervisningsmateriell | Norwegian list of categories for books and other material used in education | 6 | |
| 46 | Norsk DDK | Norwegian version of Dewey Decimal Classification | 6 | |
| 47 | Varugrupper | Swedish bookselling subject categories | 7 | |
| 48 | SAB | Swedish classification scheme | 7 | |
| 49 | Läromedelstyp | Swedish bookselling educational subject type | 7 | 28 |
| 50 | Förhandsbeskrivning | Swedish publishers preliminary subject classification | 7 | |
| 51 | Spanish ISBN UDC subset | Controlled subset of UDC codes used by the Spanish ISBN Agency | 7 | |
| 52 | ECI subject categories | Subject categories defined by El Corte Inglés and used widely in the Spanish book trade | 7 | |
| 53 | Soggetto CCE | Classificazione commerciale editoriale (Italian book trade subject category based on BIC). CCE documentation available at https://www.ie-online.it/CCE2_2.0.pdf | 7 | |
| 54 | Qualificatore geografico CCE | CCE Geographical qualifier | 7 | |
| 55 | Qualificatore di lingua CCE | CCE Language qualifier | 7 | |
| 56 | Qualificatore di periodo storico CCE | CCE Time Period qualifier | 7 | |
| 57 | Qualificatore di livello scolastico CCE | CCE Educational Purpose qualifier | 7 | |
| 58 | Qualificatore di età di lettura CCE | CCE Reading Level Qualifier | 7 | |
| 59 | VdS Bildungsmedien Fächer | Subject code list of the German association of educational media publishers, formerly at http://www.bildungsmedien.de/service/onixlisten/unterrichtsfach_onix_codelist27_value59_0408.pdf. Deprecated – use Thema subject category (eg YPA – Educational: Arts, general) instead, and add a Thema language qualifier (eg 2ACB – English) for language teaching | 7 | 60 |
| 60 | Fagkoder | Norwegian primary and secondary school subject categories (fagkoder), see http://www.udir.no/ | 7 | 28 |
| 61 | JEL classification | Journal of Economic Literature classification scheme | 7 | |
| 62 | CSH | National Library of Canada subject heading (English) | 9 | |
| 63 | RVM | Répertoire de vedettes-matière Bibliothèque de l’Université Laval) (French) | 9 | 34 |
| 64 | YSA | Finnish General Thesaurus (Finnish: Yleinen suomalainen asiasanasto). See https://finto.fi/ysa/fi/ (in Finnish). Deprecated. No longer updated, and replaced by YSO (see code 71) | 8 | 58 |
| 65 | Allärs | Swedish translation of the Finnish General Thesaurus (Swedish: Allmän tesaurus på svenska). See https://finto.fi/allars/sv/ (in Swedish). Deprecated. No longer updated, and replaced by YSO (see code 71) | 8 | 58 |
| 66 | YKL | Finnish Public Libraries Classification System (Finnish: Yleisten kirjastojen luokitusjärjestelmä). See https://finto.fi/ykl/fi/ (in Finnish), https://finto.fi/ykl/sv/ (in Swedish), https://finto.fi/ykl/en/ (in English) | 8 | 58 |
| 67 | MUSA | Finnish Music Thesaurus (Finnish: Musiikin asiasanasto). See https://finto.fi/musa/fi/ (in Finnish). Deprecated, and replaced by YSO (see code 71) | 8 | 58 |
| 68 | CILLA | Swedish translation of the Finnish Music Thesaurus (Swedish: Specialtesaurus för musik). See https://finto.fi/musa/sv/ (in Swedish). Deprecated, and replaced by YSO (see code 71) | 8 | 58 |
| 69 | Kaunokki | Finnish thesaurus for fiction (Finnish: Fiktiivisen aineiston asiasanasto). See https://finto.fi/kaunokki/fi/ (in Finnish). Deprecated. No longer updated, and replaced by Kauno and SLM (see codes D0 and D1) | 8 | 58 |
| 70 | Bella | Swedish translation of the Finnish thesaurus for fiction (Swedish: Specialtesaurus för fiktivt material:). See https://finto.fi/kaunokki/sv/ (in Swedish). Deprecated. No longer updated, and replaced by Kauno and SLM (see codes D0 and D1) | 8 | 58 |
| 71 | YSO | General Finnish Ontology (Finnish: Yleinen suomalainen ontologia). See https://finto.fi/yso/fi/ (in Finnish), https://finto.fi/yso/sv/ (in Swedish), https://finto.fi/yso/en/ (in English) | 8 | 58 |
| 72 | PTO | Finnish Geospatial Domain Ontology (Finnish: Paikkatieto ontologia). See https://finto.fi/pto/fi/ (in Finnish), https://finto.fi/pto/sv/ (in Swedish), https://finto.fi/pto/en/ (in English) | 8 | 58 |
| 73 | Suomalainen kirja-alan luokitus | Finnish book trade categorisation | 8 | |
| 74 | Sears | Sears List of Subject Headings | 9 | |
| 75 | BIC E4L | BIC E4Libraries Category Headings, formerly at http://www.bic.org.uk/51/E4libraries-Subject-Category-Headings/ but replaced by UK Standard Library Categories (code 92). Deprecated | 9 | 61 |
| 76 | CSR | Code Sujet Rayon: subject categories used by bookstores in France | 11 | |
| 77 | Suomalainen oppiaineluokitus | Finnish school subject categories. See https://www.onixkeskus.fi/media/f/5722 | 11 | 60 |
| 78 | Japanese book trade C-Code | See https://isbn.jpo.or.jp/doc/08.pdf#page=44 (in Japanese) | 12 | 54 |
| 79 | Japanese book trade Genre Code | | 12 | |
| 80 | Fiktiivisen aineiston lisäluokitus | Finnish fiction genre classification. See https://finto.fi/ykl/fi/page/fiktioluokka (in Finnish), https://finto.fi/ykl/sv/page/fiktioluokka (in Swedish), https://finto.fi/ykl/en/page/fiktioluokka (in English) | 13 | 58 |
| 81 | Arabic Subject heading scheme | | 13 | |
| 82 | Arabized BIC subject category | Arabized version of BIC subject category scheme developed by ElKotob.com | 13 | |
| 83 | Arabized LC subject headings | Arabized version of Library of Congress scheme | 13 | |
| 84 | Bibliotheca Alexandrina Subject Headings | Classification scheme used by Library of Alexandria | 13 | |
| 85 | Postal code | Location defined by postal code. Format is two-letter country code (from List 91), space, postal code. Note some postal codes themselves contain spaces, eg ‘GB N7 9DP’ or ‘US 10125’ | 14 | |
| 86 | GeoNames ID | ID number for geographical place, as defined at http://www.geonames.org (eg 2825297 is Stuttgart, Germany, see http://www.geonames.org/2825297) | 14 | |
| 87 | NewBooks Subject Classification | Used for classification of academic and specialist publication in German-speaking countries. See http://www.newbooks-services.com/de/top/unternehmensportrait/klassifikation-und-mapping.html (German) and http://www.newbooks-services.com/en/top/about-newbooks/classification-mapping.html (English) | 14 | |
| 88 | Chinese Library Classification | Subject classification maintained by the Editorial Board of Chinese Library Classification. See http://cct.nlc.gov.cn for access to details of the scheme | 15 | |
| 89 | NTCPDSAC Classification | Subject classification for Books, Audiovisual products and E-publications formulated by China National Technical Committee 505 | 15 | |
| 90 | Season and Event Indicator | German code scheme indicating association with seasons, holidays, events (eg Autumn, Back to School, Easter) | 18 | |
| 91 | GND | (de: Gemeinsame Normdatei) Integrated Authority File used in the German-speaking countries. See https://www.dnb.de/DE/Professionell/Standardisierung/GND/gnd_node.html (German) and https://www.dnb.de/EN/Professionell/Standardisierung/GND/gnd_node.html (English). Combines the PND, SWD and GKD into a single authority file, and should be used in preference to the older codes | 18 | 66 |
| 92 | BIC UKSLC | UK Standard Library Categories, the successor to BIC’s E4L classification scheme. See https://bic.org.uk/resources/uk-standard-library-categories/ | 19 | 61 |
| 93 | Thema subject category | International multilingual subject category scheme – see https://ns.editeur.org/thema | 20 | |
| 94 | Thema place qualifier | | 20 | 42 |
| 95 | Thema language qualifier | | 20 | |
| 96 | Thema time period qualifier | | 20 | |
| 97 | Thema educational purpose qualifier | | 20 | |
| 98 | Thema interest age / special interest qualifier | | 20 | 21 |
| 99 | Thema style qualifier | | 21 | |
| A2 | Ämnesord | Swedish subject categories maintained by Bokrondellen | 22 | |
| A3 | Statystyka Książek Papierowych, Mówionych I Elektronicznych | Polish Statistical Book and E-book Classification | 23 | |
| A4 | CCSS | Common Core State Standards curriculum alignment, for links to US educational standards. <SubjectCode> uses the full dot notation. See http://www.corestandards.org/developers-and-publishers | 26 | |
| A5 | Rameau | French library subject headings | 24 | 34 |
| A6 | Nomenclature discipline scolaire | French educational subject classification, URI http://data.education.fr/voc/scolomfr/scolomfr-voc-015GTPX | 24 | 48 |
| A7 | ISIC | International Standard Industry Classification, a classification of economic activities. Use for books that are about a particular industry or economic activity. <SubjectCode> should be a single letter denoting an ISIC section OR a 2-, 3- or 4-digit number denoting an ISIC division, group or class. See http://unstats.un.org/unsd/cr/registry/isic-4.asp | 26 | |
| A8 | LC Children’s Subject Headings | Library of Congress Children’s Subject Headings: LCSHAC supplementary headings for Children’s books | 28 | |
| A9 | Ny Läromedel | Swedish bookselling educational subject | 28 | |
| B0 | EuroVoc | EuroVoc multilingual thesaurus. <SubjectCode> should be a EuroVoc concept dc:identifier (for example, 2777, ‘refrigerated products’). See http://eurovoc.europa.eu | 29 | |
| B1 | BISG Educational Taxonomy | Controlled vocabulary for educational objectives. See https://www.bisg.org/products/recommendations-for-citing-educational-standards-and-objectives-in-metadata | 29 | 60 |
| B2 | Keywords (not for display) | For indexing and search purposes, MUST not be displayed. Where multiple keywords or keyword phrases are sent, this should be in a single instance of the <SubjectHeadingText> element, and it is recommended that they should be separated by semi-colons. Use of code B2 should be very rare: use B2 in preference to code 20 only where it is important to show the keyword list is specifically NOT for display to purchasers (eg some keywords for a medical textbook may appear offensive if displayed out of context) | 33 | 34 |
| B3 | Nomenclature Diplôme | French higher and vocational educational subject classification, URI http://data.education.fr/voc/scolomfr/scolomfr-voc-029 | 34 | 48 |
| B4 | Key character names | For fiction and non-fiction, one or more key names, provided – like keywords – for indexing and search purposes. Where multiple character names are sent, this should be in a single instance of <SubjectHeadingText>, and multiple names should be separated by semi-colons. Note <NameAsSubject> should be used for people who are the central subject of the book. Code B4 may be used for names of lesser importance | 35 | 42 |
| B5 | Key place names | For fiction and non-fiction, one or more key names, provided – like keywords – for indexing and search purposes. Where multiple place names are sent, this should in a single instance of <SubjectHeadingText>, and multiple names should be separated by semi-colons. Only for use in ONIX 3.0 or later | 42 | |
| B6 | FAST | Faceted Application of Subject Terminology, OCLC subject scheme derived from LCSH (see code 04). See https://fast.oclc.org/fast/. Codes are up to 8 digits, for example 1726640 for Historical fiction (see https://id.worldcat.org/fast/1726640). Only for use in ONIX 3.0 or later | 47 | 66 |
| B7 | NGSS | Next Generation Science Standards for K-12 education in the USA (https://www.nextgenscience.org). <SubjectCode> is a code such as 4-PS3-2. Only for use in ONIX 3.0 or later | 48 | |
| B8 | MVB-Lesemotive | MVB classification of ‘reading rationales’, which classify unconscious motives that lead to a book purchase. Categories are assigned and maintained by MVB. Only for use in ONIX 3.0 or later. See https://vlb.de/lesemotive | 52 | |
| B9 | LOPS21 Subject module | Finnish Suomalainen oppiaineluokitus. Only for use in ONIX 3.0 or later | 52 | |
| C0 | Læreplaner-LK20 | Codes for Norwegian curriculum for primary and secondary education. Only for use in ONIX 3.0 or later. See Læreplaner-LK20 at https://www.udir.no/om-udir/data/kl06-grep/ | 53 | |
| C1 | Kompetansemål-LK20 | Codes for competency aims in the Norwegian curriculum for primary and secondary education. Only for use in ONIX 3.0 or later. See Kompetansemål-LK20 at https://www.udir.no/om-udir/data/kl06-grep/ | 53 | |
| C2 | Kompetansemålsett-LK20 | Codes for sets of competency aims in the Norwegian curriculum for primary and secondary education. Only for use in ONIX 3.0 or later. See Kompetansemålsett-LK20 at https://www.udir.no/om-udir/data/kl06-grep/ | 53 | |
| C3 | Tverrfaglige temaer-LK20 | Codes for interdisciplinary topics in the Norwegian curriculum for primary and secondary education. Only for use in ONIX 3.0 or later. See Tverrfaglige temaer-LK20 at https://www.udir.no/om-udir/data/kl06-grep/ | 53 | |
| C4 | CLIL – Type d’article scolaire | Only for use in ONIX 3.0 or later | 53 | |
| C5 | GAR – Type pédagogique | Gestionnaire d’Accès aux resources – see https://gar.education.fr/ Only for use in ONIX 3.0 or later | 53 | |
| C6 | ISCED-F | UNESCO ISCED Fields of education and training (2013), eg <SubjectCode> 0222 is ‘History and archaeology’. Only for use in ONIX 3.0 or later. See http://uis.unesco.org/sites/default/files/documents/international-standard-classification-of-education-fields-of-education-and-training-2013-detailed-field-descriptions-2015-en.pdf | 55 | |
| C7 | Klassifikationen von Spielen, Puzzles und Spielwaren | German category scheme for games, puzzles and toys. Only for use in ONIX 3.0 or later. See https://www.ludologie.de/fileadmin/user_upload/PDFs/211126_Kategorisierung_von_Spielen_Puzzles_und_Spielwaren.pdf | 56 | |
| C8 | NBVok NTSF | National Library of Norway genre and form thesaurus. Only for use in ONIX 3.0 or later. See https://www.nb.no/nbvok/ntsf | 57 | 59 |
| C9 | JPRO Genre | Subject / genre code used in Japan. Only for use in ONIX 3.0 or later | 58 | |
| D0 | KAUNO | Finnish Ontology for fiction (Finnish: Fiktiivisen aineiston ontologia). See https://finto.fi/kauno/fi/ (in Finnish), https://finto.fi/kauno/sv/ (in Swedish), https://finto.fi/kauno/en/ (in English). Only for use in ONIX 3.0 or later | 58 | |
| D1 | SLM | Finnish genre and form vocabulary (Finnish: Suomalainen lajityyppi ja muotosanasto). See https://finto.fi/slm/fi/ (in Finnish), https://finto.fi/slm/sv/ (in Swedish), https://finto.fi/slm/en/ (in English). Only for use in ONIX 3.0 or later | 58 | |
| D2 | YSO-places | General Finnish Ontology for Places (Finnish: Yleinen suomalainen ontologia – paikat). See https://finto.fi/yso-paikat/fi/ (in Finnish), https://finto.fi/yso-paikat/sv/ (in Swedish), https://finto.fi/yso-paikat/en/ (in English). Only for use in ONIX 3.0 or later | 58 | |