Once all the ideas on a card have been released, you can complete the card and remove it from your roadmap.
To complete a card, click on "Move to" and select "Completed"
This will add a date stamp for the date of completion, as well as allow you to enter a quick description of the completed card.
If there are any active ideas within the card, you can choose what to do with these ideas before marking the card as complete.
To restore a card, click on Move to and select 'Roadmap.'