Exclusion tab in delivery

Hi All,

While checking default exclusion tab present in delivery , like exclude duplicate address and recipients who no longer want to be contacted, they are defined in delivery Input form as such:

  <if expr="@deduplicate and [../@messageType] != 5">
     <set translatedExpr="'Exclude duplicate addresses.'" xpath="/ignored/humanFilter"/>
</if>

<if expr="@useBlackList">
   <set translatedExpr="[/ignored/humanFilter]+'Exclude recipients no longer wishing to be contacted. '"
xpath="/ignored/humanFilter"/>
</if>

Can someone help to understand from where these human filters are derived/ defined in system, where logic are defined?

Thanks,

Diksha