How do I delete Index Cards?

Index cards are a folder, or substorm, containing other stickies and ideas inside of it. When you delete your index card, you are deleting all of the data inside of it too. 

1. Click once on the open space in the top bar of the Index Card.
2. Click Delete in the pop-up menu to delete the Index Card.

Deleted index cards and the stickies inside of them can be recovered from your trash if there was a mistake.

Also see:
How do I create an index card/substorm?
How do I add stickies to index cards/substorms?