Types
A user of the Gropius System. The username can be used as unique identifier for GropiusUsers. IMSUsers can be linked to a GropiusUser. Note however that this link does not affect relationships, e.g. if an IMSUser is part of an Assignment, after the IMSUser was linked to a GropiusUser, the GropiusUser does not link directly to the Assignment. Therefore, to collect all Assignments, Issue participations etc. it is necessary to also request all linked IMSUsers and their Assignments etc.
A user an IMS. This user might be linked to a GropiusUser. Note that this link can change at any time. The username might not be unique. It is possible that this user never heard of Gropius, and is only known to the system due to sync adapters.
A user known to the Gropius System. This might be a user that registered directly, or a user the systems know via a sync adapter. A user can create AuditedNodes, participate in Issues and be assigned to Issues. READ is always granted.