This document presents a ODRL profile for describing the ways the core entities defined in the ODRL Information Model change over time.

It does so by extending the ODRL and Provenance, Authoring and Versioning (PAV) ontologies by adding two new concepts:

1. Temporal Objects: Entities that exist through time under a stable identifier even as they change (sometimes known as fluents).

   This model provides temporal objects for ODRL Policies, Rules, and Assets, allowing them to be tracked over time under a stable identifier.

2. Effective Times: The instant at which a version of a temporal object either becomes (effective from) or ceases to be (effective to) a valid statement.

So, the changes in an entity over time are captured by versioning the temporal object and specifying the effective intervals of these versions. Using these extensions, we can describe how an entity as it is now, once was, and will be.

Leaving the temporal object to take the temporal strain, the versions are simple ODRL entities but with effective from and/or effective to values.

The profile also provides temporal analogues of ODRL's permission, prohibition, and duty properties pointing not to the ODRL entities themselves but to their temporal objects.

Introduction

Things change. The rights and obligations controlling the use of data develop as time passes. By providing a temporal model for ODRL, we can ensure that parties in a supply chain share the same view of the past, the present, and the future.

Such a model enables us, for example, to:

• Support audits: The model must support an account of history that both the data Provider and the data Consumer can agree upon through the audit process.
• Ensure compliance as policies update: The model must continue to support provably-correct compliance decisions in the present as policies change and update over time.
• Enable forecasting: The model must support an account of the future so actors in the supply chain can predict their capabilities and costs as and when updates are published.

The introduction of a temporal object to act as a light-weight container for the various versions of a relevant entity allows us to satisfy these use cases while maintaining a stable identifier for these entities across time.

For example, we might not want to mint a new permission with a new identifier every time the permission's price changes, especially if that identifier is stored in multiple systems. Instead, we store the temporal permission ID and version it - or, more likely in this case, version the payment duty to which it points.

                            :T1     a                       tpl:TemporalAgreement ;
                                    pav:hasVersion            :T1-V1 , :T1-V2 , :T1-V3 . 
                            

                            :T1-V1  a                       odrl:Agreement ;
                                    tpl:effectiveTo         "2020-01-01T00:00:00Z"^^xsd:dateTime
                                    tpl:permission  :T-P1 . 
                            

                            :T1-V2  a                       odrl:Agreement ;
                                    tpl:effectiveFrom       "2020-01-01T00:00:00Z"^^xsd:dateTime
                                    tpl:effectiveTo         "2024-01-01T00:00:00Z"^^xsd:dateTime
                                    tpl:permission  :T-P1 , :T-P2 .   
                            

                            :T1-V3  a                       odrl:Agreement ;
                                    tpl:effectiveFrom       "2024-01-01T00:00:00Z"^^xsd:dateTime
                                    tpl:permission  :T-P1 , :T-P2 , :T-P3 .   
                        

                                :TP-1   a                      tpl:TemporalPermission ;
                                        tpl:version            :P1-V1 , :P1-V2 . 
                                

                                :P1-V1  a                      odrl:Permission ;
                                        tpl:effectiveTo        "2020-01-01T00:00:00Z"^^xsd:dateTime
                                        ... 
                                        odrl:action            odrl:display , odrl:distribute ; 
                                        ... 
                                

                                :P1-V2  a                       odrl:Permission ;
                                        tpl:effectiveFrom       "2020-01-01T00:00:00Z"^^xsd:dateTime
                                        ... 
                                        odrl:action             odrl:display ; 
                                        ...