what will be the condition to check if DFF Attribute1 is null in journal approval template

Summary:

what will be the condition to check if DFF Attribute1 (at Journal Batch level) is null in journal approval template in oracle fusion? We have three values 001,002 and 003 for the DFF. We need to write an auto-reject rule in case user does not select any of the DFF values while creating the journal.

We tried with Not In (001,002,003) but it does not work. We tried Is NULL which does not work as well. We even tried NOT 001 as well as Not starts with 0,, but both does not work. So please guide us what should be the condition to be put in Journal approval template.