Publishing WG Telco, 2018-06-11: “Cover” in the infoset, JSON terms for reading order and resources

See minutes online for a more detailed record of the discussions.


It was not finalized what the exact representation of the Infoset item “cover” would be in terms of JSON-LD and Schema.org. Cover for a book may or may not be an image , ie, the purely image oriented terms may not be enough, and it is also up to the author to use, a resource used elsewhere, and whether it is in the reading order.

The alternative is to use cover as part of the structural items, ie, as part of the reading order list or the list or resources. The issue there is that the Schema.org <a href="StructuredValue“>http://schema.org/StructuredValue (which was considered as a generic type for such usage) type may be too restrictive in so far as it can only appear as the value of some properties, and there is no way to express something like the IANA rel values.

The decision was to define an alternative, and targeted, type to replace StructuredValue, and use that for, e.g., cover. That could also be used for, e.g., privacy policy. It was agreed to define such a structure as part of a PR on github.

Proposed context

The github discussion on various issues have brought forward the necessity to have our own JSON-LD @context file: own terms for resources and reading order, setting the order sensitivity for, say, author (i.e., "author": {"@container":"@list"}), etc. The context file is at: https://github.com/w3c/wpub/blob/master/common/context.jsonld, with the official URL at https://www.w3.org/ns/wpub.jsonld (the latter is redirected to the former for now).

Bikeshedding on terms

The result:

  • the JSON-LD term readingOrder is used for the “reading order” infoset item
  • the JSON-LD term resources is used for the “resources” infoset item