Importing "empty"/null Updates from CSV

If I import a CSV file to match & update data why does a null value not replace an existing value, shouldn’t it on an update (and if not, could it be an import option?)

For example if I have a text field called Widget in Tadabase and it contains and “X”, if my CSV import file has a value of “Y”…


…the record value is updated as expected but if I want to replace the existing value with a null I can’t seem to do it, neither of these two formats work :



I know I could force a space in there and then run a rule to clean it up but that’s not practical when you have hundreds fields this applies to.