| DisplayName | Description | ID | Source | Target | Type | Accessibility | Abstract |
| Designer | A user who is assigned an activity to edit the activity, its properties, and any activities it contains. | System.ActivityCanBeEditedByUser | System.WorkItem.Activity | System.User | System.Reference | Public | False |
| Followed By Activity | Followed By Activity | System.ActivityFollowedByActivity | System.WorkItem.Activity | System.WorkItem.Activity | System.Reference | Public | False |
| Depends on Work Item | Depends on Work Item | System.DependentActivityDependsOnWorkItem | System.WorkItem.Activity.DependentActivity | System.WorkItem | System.Reference | Public | False |
| Reviewers | Reviewers | System.ReviewActivityHasReviewer | System.WorkItem.Activity | System.Reviewer | System.Membership | Public | False |
| Is User | Is User | System.ReviewerIsUser | System.Reviewer | System.User | System.Reference | Public | False |
| Voted By User | Voted By User | System.ReviewerVotedByUser | System.Reviewer | System.User | System.Reference | Public | False |
| Contains Activity | Contains Activity | System.WorkItemContainsActivity | System.WorkItem | System.WorkItem.Activity | System.Membership | Public | False |