You can define a field reference name using alphanumeric, underscore, and hyphen characters. Each field reference name must contain at least one period, (.), but no period can appear at the start or the end of the name. A field reference name cannot start with a number or an underscore, and a field reference name cannot have multiple consecutive hyphens, such as (--).
Examples
The following examples show valid field reference names, in various namespaces.
System Namespace Examples
System.Id
System.Title
System.CreatedBy
System.CreationDate
System.ChangedBy
System.ChangedDate
System.State
System.Reason
Microsoft Namespace Examples
Microsoft.Common.Status
Microsoft.Common.Priority
Microsoft.Scheduling.Duration
Microsoft.Scheduling.PercentComplete
Microsoft.Testing.TestCaseName
Examples in Other Namespaces
Customers and partners can also define their own namespaces to support their custom work item types. For example, the fictitious company Trey Research might define the following custom work item types:
TreyResearch.Common.Severity
The fictitious software company A. Datum Corporation might define the following work item types:
A_Datum.Common.BusinessPriority
Field reference names can be up to 70 characters in length.
Team Foundation Server prevents you from creating your own System.X field because it might impede Team Foundation Server functionality.
Team Foundation Server does not prevent you from creating your own Microsoft.X field. However, this practice is strongly discouraged because it might impede Team Foundation Server functionality.
See Also