| 01 | Proprietary | For example, publisher’s own series ID. Note that <IDTypeName> is required with proprietary identifiers | 0 | |
| 02 | ISSN | International Standard Serial Number, unhyphenated, 8 digits | 0 | |
| 03 | German National Bibliography series ID | Maintained by the Deutsche Nationalbibliothek | 0 | |
| 04 | German Books in Print series ID | Maintained by VLB | 1 | |
| 05 | Electre series ID | Maintained by Electre Information, France | 1 | |
| 06 | DOI | Digital Object Identifier (variable length and character set, beginning ‘10.’ and without https://doi.org/ or the older http://dx.doi.org/) | 6 | 65 |
| 15 | ISBN-13 | Use only where the collection (series or set) is available as a single product | 15 | |
| 22 | URN | Uniform Resource Name using full URN syntax, eg urn:issn:1476-4687 – though where a specific code for the identifier type is available, use of that code (ie code 02 for ISSN) is preferred | 8 | 62 |
| 27 | JP Magazine ID | Japanese magazine identifier, similar in scope to ISSN. Five digits to identify the periodical, without any hyphen or two digit extension. Only for use in ONIX 3.0 or later | 62 | |
| 29 | BNF Control number | French National Bibliography series ID. Identifiant des publications en série maintenu par la Bibliothèque Nationale de France | 24 | 36 |
| 35 | ARK | Archival Resource Key, as a URL (including the address of the ARK resolver provided by eg a national library) | 36 | |
| 38 | ISSN-L | International Standard Serial Number ‘linking ISSN’, used when distinct from the serial ISSN. Unhyphenated, 8 digits. Only for use in ONIX 3.0 or later | 41 | |