Often time there are small steps/items that need to be remembered for a particular task. It's too granular to be it's own task, but it would be helpful for the user/resource to be able to add a checklist/to-do list to their own task and for a checklist to be added to templates.
For example, an article creation task may have the following to-dos:
Update editorial calendar - Takes less than 5 minutes
Create writing assignment - Takes 15 minutes
Send writing assignment - Takes less than 5 minutes
Writing assignment accepted - Just a reminder to check in