Unable to define Eligibility based on Religion which is null

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Hi All,

We have a requirement to define Eligibility for an absence such that only Religion given as 'Muslim' or Null, should be eligible for the absence. All other Religions should not be eligible.

I cannot define this in Eligibility Profiles because I cannot give a condition to select null value.

I can see that the PER_RELIGIONS table will not have any data if the Religion field is not populated. Also there's no DBI or Input variable to fetch person's religion.

How can I define eligibility such that Person with null religion value should be eligible for the absence?