Reopening a task
Any assignee or author can reopen a completed task.
If an assignee reopens a task, it is reopened for that assignee and the author only.
If the author reopens it, it is reopened for everyone.
To reopen a task, go to the Completed folder on the home screen or the completed tasks list inside a project, and uncheck the checkbox next to the task.

The task will be reopened in its original project with all previously entered data intact.
The task history (including reopening) is shown in the task card under the «History & Comments» section.