Documentation on Namecards and "Invite by URL"

Where can I get documentation on setting up Namecards? There is no information on setting these up, nor detailed instructions on using the "Invitation by URL." The link to Namecard just displays the three selections and the "Generate Code" button with no instructions on how to use it. The link to "Invite by URL" merely provides the link in a box. Nothing explains how to use it or transfer it to another medium. The documentation is non-existent on most other of the features. Am I missing something somewhere?

In your webinar and elsewhere you describe being able to create business cards with URL link and invitation code (is this the URL code?) personalized with code of user that is inviting people to site. Where are instructions for this? I have looked through the site as well as You Tube with no luck.

Thank you in advance for your reply.