JIRA Workflows - JIRA 6.x Administration Topic - page 156

How to do it…
Perform the following steps to make the Reason for Backlog field required during the
Move to Backlog transition:
1. Select and edit the Simple Workflow .
2. Select the Diagram mode.
3. Click on the Move to Backlog global workflow transition.
4. Click on the Validators link from the panel on the right-hand side.
5. Click on Add validator , select the Fields Required validator from the list, and
click on Add .
6. Select the Reason for Backlog field from Available fields and click on Add >> .
This will add the selected field to the Required fields list:
7. Click on the Add button to complete the validator setup.
8. Click on Publish Draft to apply the change.
After you have added the validator, if you try to execute the Move to Backlog transition
without specifying a value for the Reason for Backlog field, JIRA will prompt you with an
error message as shown in the following screenshot: