Some Checkboxes in PERFECT FIT may use Boolean Fields: Yes/No.
In the computer world, a boolean field may have 3 states: Yes, No, and Null, or empty.
A checked box is Yes, and an unchecked box is No or Empty. Thus, you can not search on the value No and expect to find all unchecked checkboxes.
The mathematical equivalent is 1 for Yes, 0 for No, and __ nothing for empty.
To search on checked checkboxes, use the comparison value = 1
To search on unchecked checkboxes, use the comparison value <> 1