According to an announcement on Richard Turner’s blog, Windows CardSpace finally has an icon to symbolize that a site or application supports Information Cards. This visual icon has been missing since Windows CardSpace was introduced.
It is important to note that this is not a Windows CardSpace icon.
You are free to use this icon (following the usage guidelines) to provide a clear, consistent visual cue to your users that your sites and applications support Information Cards. Make sure to download the Information Card Icon package which contains usage guidelines, FAQ, and a series of pre-rendered PNG images in different sizes along with the master Illustrator artwork.