| DisplayName | Description | ID | Base Class | Abstract | Hosted | Singleton | Group | Extension | Accessibility | ElementId |
![System.WorkItem](/images/ClassType.png) | Work Item | Defines the basic properties of work items | System.WorkItem | System.Entity | True | False | False | False | False | Public | eebf4a11-643f-131e-4bcc-aedc4014f69f |
![System.WorkItem.ActionLog](/images/ClassType.png) | Work Item Action Log | Work item action logs, such as logging about automatic actions | System.WorkItem.ActionLog | System.WorkItem.Log | True | False | False | False | False | Public | 9804e354-b5b8-5954-0d1f-95b3fd185bde |
![System.WorkItem.BillableTime](/images/ClassType.png) | Billable Time | Billable time | System.WorkItem.BillableTime | System.WorkItem.Log | False | False | False | False | False | Public | a4dd7075-adc2-4d02-b7b4-dba10601a399 |
![System.WorkItem.CommentLog](/images/ClassType.png) | Work Item Comments Log | All comments associated with work items in the action log | System.WorkItem.CommentLog | System.WorkItem.Log | True | False | False | False | False | Public | 13789634-4663-cb70-edc5-e8da26450f62 |
![System.WorkItem.Log](/images/ClassType.png) | Work Item Log | All log entries associated with work items, such as the action log and notification log | System.WorkItem.Log | System.Information | True | False | False | False | False | Public | 00b84200-fbbf-d0af-1347-8c489b52bca3 |
![System.WorkItem.NotificationLog](/images/ClassType.png) | Work Item Notification Log | Notification logs for work items | System.WorkItem.NotificationLog | System.WorkItem.Log | True | False | False | False | False | Public | b869fff4-0191-d958-26fd-203895d693bb |
![System.WorkItem.TroubleTicket](/images/ClassType.png) | Trouble Ticket | Trouble ticket | System.WorkItem.TroubleTicket | System.WorkItem | True | False | False | False | False | Public | 92595a79-8509-2243-5792-05564d5406ff |
![System.WorkItem.TroubleTicket.ActionLog](/images/ClassType.png) | Trouble Ticket Action Log | Trouble ticket action logs | System.WorkItem.TroubleTicket.ActionLog | System.WorkItem.ActionLog | False | False | False | False | False | Public | b455dd44-4be6-3ece-f40b-f333c3c66530 |
![System.WorkItem.TroubleTicket.AnalystCommentLog](/images/ClassType.png) | Trouble Ticket Analyst Comments | Analyst comments on trouble tickets | System.WorkItem.TroubleTicket.AnalystCommentLog | System.WorkItem.CommentLog | False | False | False | False | False | Public | 5dea31b9-b762-5003-b9d1-64fa5feb66e4 |
![System.WorkItem.TroubleTicket.AuditCommentLog](/images/ClassType.png) | Trouble Ticket Audit Log | Trouble Ticket audit logs | System.WorkItem.TroubleTicket.AuditCommentLog | System.WorkItem.CommentLog | False | False | False | False | False | Public | 936d3b33-55b0-38ec-a0a5-c2277c48ede1 |
![System.WorkItem.TroubleTicket.NotificationLog](/images/ClassType.png) | Trouble Ticket Notification Log | All notification logs for trouble tickets, such as e-mail and text message notifications | System.WorkItem.TroubleTicket.NotificationLog | System.WorkItem.NotificationLog | True | False | False | False | False | Public | 9dacbb7d-de25-7ae4-a225-494496254e3d |
![System.WorkItem.TroubleTicket.SipNotificationLog](/images/ClassType.png) | Text Message Notification Log for Trouble Tickets | Notification logs for text message (SIP) notifications about trouble tickets | System.WorkItem.TroubleTicket.SipNotificationLog | System.WorkItem.TroubleTicket.NotificationLog | False | False | False | False | False | Public | e5542821-f397-5042-ba27-122bc0aff534 |
![System.WorkItem.TroubleTicket.SmtpNotificationLog](/images/ClassType.png) | E-Mail Notification Log for Trouble Tickets | Notification logs for e-mail (SMTP) notifications about trouble tickets | System.WorkItem.TroubleTicket.SmtpNotificationLog | System.WorkItem.TroubleTicket.NotificationLog | False | False | False | False | False | Public | 5682a3c2-84c5-64bb-54ec-034b356a146f |
![System.WorkItem.TroubleTicket.UserCommentLog](/images/ClassType.png) | Trouble Ticket User Comments | User comments on trouble tickets | System.WorkItem.TroubleTicket.UserCommentLog | System.WorkItem.CommentLog | False | False | False | False | False | Public | f155948d-e113-491b-b487-cf3117fd8e6d |
![System.WorkItemGroup](/images/ClassType.png) | Work Item Group | Group of all work items | System.WorkItemGroup | System.Collections | True | False | False | False | False | Public | 98deda7e-b0ac-1022-2345-6f5ca46c3995 |