JIRA Workflows - JIRA 6.x Administration Topic - page 143

How to do it…
We need to create a new custom field configuration scheme in order to set up a new set of
select list options:
1. Select and edit the workflow to configure.
2. Select the Diagram mode.
3. Click on the Move to Backlog global workflow transition.
4. Click on the Post functions link towards the right-hand side.
5. Click on Add post function , select Clear Field Value post function from the list,
and click on Add .
6. Select the Reason for Backlog field from Field and click on the Add button.
7. Click on Publish Draft to apply the change.
With the post function in place, after you have executed the transition, the Reason for
Backlog field will be cleared out. You can also see from the issue's change history as a part
of the transition execution that where the Status field is changed from Backlog to Open ,
the change for the Reason for Backlog field is also recorded.