Roam will try to automatically handle URLs to websites and files in the info panel. It will also try and display a file based, base64, or binary image. If all else fails it will just display the string value.
Link format
Links to websites should start wtih http:// and links to files should start with file:///. Roam will check for both these and try to create a valid URL.
Replace URL with alias
The full URL can be aliased by appending |alias to the end of the URL string. Example http://google.com|Google will just display as Google as a hyperlink in the info panel.