Unit Type Data files have an extension of .ctu.  Using the dialog box, navigate to
the desired folder, selected the desired file and click Open.  This will import all Unit Type
Data in the selected file.  Note that any Unit Types already in the current drawing of the
same name as imported unit types will be overwritten. Users should rename any
existing Unit Types before importing.

Land Planner Suite installs some sample Unit Types.  The file is cadtracts Sample Unit.ctu
and can be found in the install folder (default is Program Files/CadTracts/LandPlannerSuite).