Re: Readium LCP REL mapping to ODRL

Dear ODRL WG members, 

I've been in touch with R. Iannella and M.Steidl about ODRL and its possible use as a REL for the Readium LCP DRM. 

The Readium LCP specs can be found at https://readium.github.io/readium-lcp-specification/ <https://readium.github.io/readium-lcp-specification/>.

After reviewing the latest spec, and will just offer some comments:
- the properties used in Readium LCP are so basic (date start, date end, #pages one can print, #characters one can copy) that the ODRL JSON-LD syntax is a bit too complex for such a small need. 
- but it would be interesting to provide a clear mapping from LCP rights to ODRL syntax, so that these rights can e.g. be stored in a triple store. 

So I took a look at the possible mapping. 

- re the license id we must handle, "@id" is a good fit. 
- I've been looking for an equivalent in ODRL of the "issued" and "updated" datetimes we use in LCP. Renato led me to https://github.com/w3c/poe/issues/48 <https://github.com/w3c/poe/issues/48>. I found "dc:issued" and "dc:modified" -> good. 
- "provider" maps to "dc:creator".
- "encryption" and "links" properties have no equivalent in ODRL, which is logical. 
- "rights" in LCP are simply a set of properties. 
  * "print" and "copy" can be mapped to permissions wit Count constrains, as Renato told me. But I suppose that "lcp:print" and "lcp:copy" left operands should be created. 
 * "start" and "end" dates can be mapped to a "Period" I guess, or a Datetime + a Delay Period, but I'm missing details about the use of Periods in odrl-vocab 4.20.6  (#term-dateTime).

Maybe the WG could enhance the spec on this odrl-vocab 4.20.6  (#term-dateTime) aspect, re. Period.

With some help from the ODRL WG, a proper mapping of LCP rights to ODRL rights can be created. Using ODRL as a vocabulary for LCP would mean 1/ changing the syntax at the time we are launching LCP, which is a no go 2/ moving the "encryption" and "links" parts of the license to JSON-LD, which is not a priority for now. 

Laurent Le Meur
CTO, EDRLab

EDRLab, 14 rue Alexandre Parodi,
75010 Paris