Variable Nullify Method

In one of the Hive tutorials, it says that a variable can be nullified by apointing to something that comes out with no value. Examples:
UNIT VARIABLE:
Set Unit = No Unit

ANOTHER FORM OF UNIT VARIABLE:
Set Unit = Dying Unit (In this case, if there is nothing comes out as "dying unit" it should be nullified automatically)

POINT VARIABLE
instead of "call udg loc" custom script line, using this:
Set Location = (Center of No region)
That should come up with no value and it will nullfy the variable. Can you verify all of this information?

for the point i think that returns Center of playable map area, if the lable is not found, cant guarentee the unit though.

If the function does not match the event, it returns null. But it's pretty unsafe to do so, plus it's an extra function call.

Every veriable set to non-existing value returns 'null'

Is "Center of No Region" one of them?