To Set a Reference Datum
1. Define the active annotation orientation before creating the first annotation in any session.
2. On the Model Tree or in the graphics window, right-click a datum plane or datum axis and click Properties. The Datum or Axis dialog box opens.
◦ Under Type, 
is selected by default.
is selected by default. | You can also open Datum or Axis dialog box by clicking Properties on the shortcut menu that appears when you right-click a datum plane or a datum axis, respectively, on the Model Tree or in the graphics window. |
3. If required, type a new name in the Name box of the Datum dialog box and click OK.
| | • You can change the name by choosing Name from the PART SETUP or ASSEM SETUP menu. • You can blank a reference datum plane only by placing it on a layer and then blanking the layer. • The On Surface and Define options in the Datum dialog box are used to create 3D datums in drawings. • To return the datum to its unset state, click  . |