Use the Lookup button to the right of the field to select a UDT10 to link.  

Note: If you are using the Costpoint multicompany feature and are tracking leave by UDT02, only those UDT02s assigned to the Costpoint company on the Basic Information tab will display in the Lookup.

This non-editable field displays the UDT10 description.

Select the OK pushbutton to close the Add UDT10 Link dialog and to populate the UDT10 Links tab with the link information.  

Press the Cancel pushbutton to close the Add UDT10 Link dialog and return to the UDT10 Links tab.