In the Version Tree Browser window, display
the version tree for the element.
Select a version in the Version Tree Browser display.
Click Tools > Apply
Label.
In the Version Labels window, select a label type
from the list.
To move any label that may have been previously applied
to another version to the version selected in Step 2, select Move
label if label already attached to element.
Tip: If a label of the type specified in
Step 4 is attached to another version of this element, and you do not select
this option, the operation fails. The label does not move to the version selected
in Step 2.