A PartyDigitalIdentity enables identification / authentication of a unique Party or many PartyRoles.<br/><br/>A PartyDigitalIdentity identifying only PartyRoles might be used for permissions delegated.<br/><br/>Or a PartyDigitalIdentity may identify a Party but only for a subset of the PartyRoles he plays. For example, it can be used to have a PartyDigitalIdentity carrying all professional PartyRoles delegated by the employer and another one carrying all PartyRoles played personally.<br/>