Font Size:



ONIX for Publications Licenses (ONIX-PL) is an XML format for the communication of license terms for digital publications in a structured and substantially encoded form, designed to serve the interests of all parties in the licensing chain. ONIX-PL is specialized to handle the licenses under which libraries and other institutions use digital resources, particularly but by no means exclusively electronic journals. It builds on the work of the Digital Library Federation's Electronic Resource Management Initiative (ERMI) and joint EDItEUR/NISO work, first on ONIX for Serials and later on ONIX-PL itself; and it has benefited from funding contributions from the Publishers Licensing Society (PLS) and the Joint Information Systems Committee (JISC).

As the number of digital resources in library collections grows, libraries have increasing difficulty in managing, and ensuring compliance with, the correspondingly growing number of different licenses that they hold. ONIX-PL enables libraries to:

  • express licenses in a machine-readable format
  • load them into electronic resource management systems
  • link them to digital resources
  • communicate key usage terms to users
  • compare terms from different licenses

Publishers or other licensors can also benefit from the ability to maintain their licenses in a standard machine-readable form.

The ONIX-PL standard consists of an XML schema definition and a free-standing Dictionary of controlled terms, incorporated into the schema as a separate file. After an extended period of development and testing, Version 1.0 of the schema definition was published in November 2008, and has remained stable since that date. The capabilities of the standard have in the meantime been extended by adding to the ONIX-PL Dictionary. This process continues, as new user requirements arise.

How ONIX-PL is used

Most library licenses are based on a model text of some kind – a publisher's standard license, or a library consortium's standard license, or a public domain model license. ONIX-PL similarly distinguishes between model licenses, or templates, and individual license instances. Ideally, an ONIX expression of a standard license will be created once only, as a template. Expressions of individual licenses, or of any recurring variants of the model, can be derived by editing the template expression. EDItEUR provides – as freely available Open Source software – an editing tool (OPLE) which can be used both to create new templates and to copy and edit them for individual use.

The XML expression which emerges from this process can then be loaded into a library system which has the necessary capability to interpret the ONIX-PL format. This requires the development of a mapping between ONIX-PL and the form in which the target system stores and manipulates license information. Such mappings have been or are being developed by library system providers. In the UK, JISC has developed and tested an online license comparison tool, ELCAT, as a service to JISC subscribing institutions.

ONIX-PL resources

ONIX-PL format specification
Version 1.0 of the ONIX-PL format specification was published in November 2008, and is still the current version.

ONIX-PL Schema v1.0

Version 1.0 of the ONIX-PL schema, expressed in W3C XML Schema format, is available for download as a ZIP file, including the most recent issue of the ONIX-PL Dictionary. It may also be possible to supply schema definitions in RELAX-NG (RNG) and RELAX-NG Compact (RNC) formats for developers who prefer them. Please email if you are interested in one of these options.

ONIX-PL examples
For a better understanding of how ONIX-PL expressions work in practice, a selection of real license expressions – with explanatory notes – can be found here.

Describing post-cancellation access in ONIX-PL
From Issue 5 of the ONIX-PL Dictionary, provision has been made to improve the description of facilities which the licensor offers for access to licensed resources after a subscription has been cancelled or the entire license has been terminated.  Explanatory notes can be downloaded here.

Open Access materials in ONIX-PL
Also from Issue 5 there is new provision for dealing with Open Access content included alongside proprietary materials covered by a license agreement.  A short guide to handling Open Access content in ONIX-PL can be downloaded here.

ONIX-PL Dictionary
More information and additional downloads relating to the ONIX-PL Dictionary are available here.

OPLE software
OPLE (the ONIX-PL Editor) is a browser-based software tool which enables users to create and edit ONIX-PL expressions. It is offered free-of-charge as Open Source software.

ONIX-PL and OPLE listserv
If you would like to keep in touch with developments in ONIX-PL and OPLE, please sign up to the ONIX-PL listserv. Notices of updates to the format and to the software are always sent to this list; and you can use it to ask questions and to participate in discussion about implementing ONIX-PL.

Terms & Conditions  |  Privacy Policy  |  Cookie Policy