Complete the following steps to update the type for added elements you created to define a reference attribute element.
On the Types pane of the Configuration dialog box, select the type for added elements you previously created.
Select the reference attribute element and click Add a type for added elements to create a new reference attribute element. Enter a name for the reference attribute element in the Name control.
In the Attributes section, click the Add a new enumeration value to add one or more available reference attribute values. Use the text control below the list of values to name each value.
Click OK to apply the changes to the project and close the Configuration dialog box.
In the Link Details view, select the same covering document section on the From pane, the same reference type from the Link type pull-down menu on the From pane, and the same requirement on the To pane that you used to create the reference.
Select the requirement in the Requirements control on the To pane. The Reference Attributes control on the To pane becomes available.
Click the Value column of the Reference Attributes control and select a value you defined for the reference attribute element.