Within the Vehicle and Client Details screen you can change the screen labels if you would prefer something other than the default.  This is done whilst in the screen and requires that you right click the label that you want to change whilst holding down the 'Shift' and 'Ctrl' keys on the keyboard, for example:

Standard labels:

Right Click whilst holding the Shift and Ctrl keys on the 'Registration Label:

We will change the label to say 'Serial' and we will change the tool tip while we are at it, we could also mark the field as required which would force the user to enter the information.

Note, for a textbox you can use the 'Caption' setting to set a descriptive name for the field in case it fails the 'Required' test.

And once we press 'Ok' we will see the new label on our vehicle details screen:

You can also set the default entry and whether a field must be filled by editing the properties of the field, again by right clicking while holding down 'Shift' and 'Ctrl' keys