Rally Queries: Why when Query has Parent is null then we still see parent results?

Products

• Rally On-Premise
• Rally SaaS

Issue/Introduction

How can we filter out the Parent field for user stories when using Custom List app?
When setting the Query to (Parent = "null") there are still stories with parents returned.

Environment

Release:
Component: ACSAAS

Resolution

Rally considers User Stories to be "parents". When opting to display the Parent column, see that it reads: Parent (User Story). 

Features are also displayed in the Parent column and there is an additional Feature column where the features are also displayed.

So, in order to have no parents displayed in the Parent column at all , the query you will need to set is;
((Parent = “null”) and (Feature = “null”))