[poe] IM: upgrade Short-cut Instances of Classes in Policy Rule Composition to a section

nitmws has just created a new issue for https://github.com/w3c/poe:

== IM: upgrade Short-cut Instances of Classes in Policy Rule Composition to a section ==
I refer to the [Information Model](https://w3c.github.io/poe/model/#) (IM) document of 23 June.

Its section [2.7 Policy Rule Composition](https://w3c.github.io/poe/model/#composition) is not only about composing the Rules of a Policy, the region starting with "An ODRL Policy may also declare multiple Assets, ..."  is about adding instances of Asset, Party or Action as properties to the Policy (called "at the Policy level") and about rules for integrating such instances into Permissions and Prohibitions. As this is a very special and important topic it should be upgraded to a section of the IM document. And I suggest to move this section before Policy Rule Composition as short-cuts have implications on Rules.

Further the IM needs a wider and more consistent view on theses so called short-cuts:

* Properties different from the ones currently defined for a Policy Class (uid, permission, prohibition, conflict, inheritAllowed, profile) have different roles a this "policy level":
  * target, assigner, assignee and action are properties which should be added to the existing permission and prohibition Rules of the Policy
  * while constraint properties must not be added to permission or prohibition rules, they may only be referenced by a Compound Constraint in one or more permissions or prohibitions
* As such properties may occur as properties of a Policy the [2.1. Policy Class](https://w3c.github.io/poe/model/#policy) section must include a statement about such occurrences. A basic part of that statement should be that these properties are not a property of the policy, they are only properties of Permissions and Prohibitions of this Policy, placed their as syntactic sugar.
In a short version this statement refers at least to the sections describing the two types of "short-cuts" (in fact constraint properties are not a short-cut).
* As target, assigner, assignee and action may be "direct" properties of a Permission or Prohibition but may occur also as shortcut instances already the sections about the Permission Class and the Prohibition Class should include a statement about that, best with a reference to the Short-cut Instances section for details.
* This item above is also a reason for putting the Short-cut Instances section prior to Policy rule Composition: first the IM must explain that properties may occur at different locations but having the same semantic role and then the Composition section can explain how multiple instances of a property need to be expanded.

Please view or discuss this issue at https://github.com/w3c/poe/issues/202 using your GitHub account

Received on Sunday, 25 June 2017 09:41:18 UTC