Filter operators
A row's filter decides which contacts can get that row. Most contacts have most fields blank, so how a blank field is treated matters as much as the values.
Is none of
Is none of passes when the contact's value is none of the ones you list, and also when the field is blank. That is what a stop rule needs: lead status is none of Active Deal, No Opportunity stops those two and still lets in everyone with no lead status yet.
For a property with options, choose is none of (blank counts as none) and tick the values. For a text property, choose is none of (separate with ;) and type the values with a semicolon between them. A contact with several ticked values (a multiple checkbox) is checked value by value.
Through the API this operator is called is_not_any_of; is_none_of is the same rule.
Is unknown (empty) and is known (not empty)
Is unknown (empty) passes when the field is missing, blank or only spaces. Is known (not empty) passes when it holds anything. Use is unknown to keep a cold opener away from anyone who came in through a form: inquiry type is unknown.
Through the API these are also called is_empty and is_not_empty.
Checking a filter
Run a dispatch preview for a test contact: every row shows whether it matched and the value it compared.