Sometimes, you no longer need a form, or wish to use a newer, better version of it.
To archive a form, access Form Details and click on the Archive this form link:
Archive this form
Once clicked the following 'are you sure' type message will appear:
Are you sure you want to archive it?
When the form is archived, it disappears from the main Form List. However, if you click the 'View archived forms' check box, it will display these with a red suffix (archived):
Archived Forms
Once archived, two options appear in the Form Details screen:
Un-archive this form
Delete this form
Un-archive and Delete a form
Obviously un-archive will restore the form back into use.
IMPORTANT
If you choose to delete the form it is gone forever.