Difference betweeen 'Filter out' and 'is not' operator


Description

In a list view, 'is not' operator under filter builder doesn't work in the same way as 'Filter out' value of a column.

Release or Environment

All releases.

Cause

If 'is not' operator is applied in the condition builder, it removes both the mentioned value as well as empty records whereas 'filter out' only removes the specified value. However, the records with empty column values still remains on the list.


Example:
Suppose, in the incident list, in the condition builder 'Assigned to' is not 'xxx' filter is applied.
It will remove all the incident records which are assigned to  'xxx' as well as unassigned incidents. (incidents with assigned to as empty)If you observe the encoded query, it is something like this: assigned_to!=<sys_id>^ORassigned_to=NULL

Now, open the incident list again(it must have 'assigned to' column ), find out an incident which is assigned to 'xxx'. Right-click on the column value 'xxx' and click on 'Filter out'. It will only remove the records that are assigned to 'xxx' but not the unassigned records. 
If you observe the encoded query in this case, it is something like this: assigned_to!=<sys_id>

As both the queries are different, it returns a different number of records in the list view which is expected.

Resolution

This is an expected behavior to ignore records with 'empty' values when you use 'Filter out'.
If you do not want to see record containing '(empty)' values for that column, you can use one for more filter to not show (empty) values for that column.