System Variable 893: Conversations: If a Task Is Set as Done by a User, and this User Adds a New Comment to a Task Conversation, then the Task Will Be Set as To-Do Again for this User

If this System Variable is selected in Settings > Global System Settings > System Variables, a task that has been set to Done by a user who is booked on the task will revert to the To-do status when the user adds a new comment to the task conversation.