What are the major differences between ONIX 2.1 and 3.0 for digital products?

What follows is a representative question from a Canadian data supplier as sent to BookNet Canada’s Bibliographic Manager Tom Richardson. Both the question and the response have been edited for clarity. Have your own question? Email us at biblio@booknetcanada.ca and discuss!


I have a question about Product forms I was hoping you could answer for me, and what you think the best way is to express them in ONIX 3.0.

In ONIX 2.1 there is the product form <ProductForm>DG</ProductForm> (Electronic Book Text), which is described as “Electronic book text in proprietary or open standard format.” This is not a supported product form in ONIX 3.0 and, looking through ONIX 3.0’s different codes, I can’t find one that matches DG. The best fit I can see is <ProductForm>EA</ProductForm> (Digital [delivered electronically]), which is described as “Digital content delivered electronically (delivery method unspecified)”. This seems more vague than DG was.

Is this meant to be clarified in the <ProductFormFeature>?


ONIX 3.0 has some major differences from 2.1 and digital products is one. When ONIX 2.1 was in primary development (years 2000 to 2005), digital products were separated as their use case had not yet been defined. With ONIX 3.0 digital products are integrated to the routine way ONIX is organized using Product Form and Product Form Detail. That change is the main reason why ONIX 2.1 uses List 7 & 78 and ONIX 3.0 needs different lists -- List 150 and 175. 

The code list “Heading” is seldom enough to fully understand the code use so the code list’s “Notes" need to be referenced. In 3.0, Product Form EA is not recommended as it doesn't specify the delivery method - see an abbreviated List 150 with its notes column below. ONIX always supports codes like EA because there’s a use case for not being able to supply information, its just not one typically needed. Most digital products are traded as "ED"  - where "download" is specified. One notable exception is audiobooks would be traded as AJ – a downloadable audio file. These require different Product Forms because they are different file type – more different than paper or hardback.


Downloadable audio file

Digital audio recording downloadable to the purchaser’s own device(s)


Digital (delivered electronically)

Digital content delivered electronically (delivery method unspecified)


Digital download and online

Digital content available both by download and by online access


Digital online

Digital content accessed online only


Digital download

Digital content delivered by download only

Generally (not always) the first character of a Product Form matches to the first character of its corresponding Product Form Detail list. For digital books ONIX 2.1 List 10 EpubType matches to ONIX 3.0 List 175 Product Form Detail’s “E___” section. In ONIX 3.0 List 150 Product Form the “D_” section is reserved for digital products on physical media with its corresponding List 175 Detail supporting a "D___" section reserved for their operating system details (and you really want to check the Notes!)

Product Form Feature does have uses for digital. But if Product-Form-Detail provides a primary description of the Product, Product-Form-Feature is used to describe another layer While sometimes it can be supplied as a free text value, most of the codes used in Product Form Features' List 79 actually refer to another ONIX Code list. So when the List 79 code is “01” the Product Form Feature Value is a code taken from List 98. This allows Product Form Feature to carry a wide variety of information needed to describe the Product – and makes it available without having to add endless new composites.

Product Form Feature has with similar support in both ONIX 2.1 and 3.0 but if no Product Form Detail from ONIX 2.1’s List 78 map to it, PF-Features has expanded uses in ONIX 3.0. Of particular interest to digital products are:

  • Accessibility code list 196

  • Epublication format version is supported (Accessibility options can depend this)

    • from code list 220 or as free text

  • Text Fonts (can be needed for Accessibility)

  • Operating system (hand held or computer operating system required)

    • from code list 176 or as free text

  • Version of the epublication validator used

  • Authentication and access controls.

Another major change for ONIX 3.0’s digital support is that the <EpubUsageConstraint> composite exists at both the Product level and within the Price level. The former is used for constraints that apply at the ISBN level: constraints that apply to any product sold under the ISBN, while the latter handles the scenarios where the ISBN has different options for rental, subscription, licensing, and so on.  At the Price level the constraints would be the ones at the Product level plus any constraint that applies to the specific option specified by the Price.