The banner url (banner) is optional but if included should be a web accessible url.
In order to be displayed the banner url should begin with http:// and end in .gif, .jpg or .png
The banner should be a exactly 80 pixels high by 720 pixels wide
Background color (bgcolor) is optional and defaults to 000000.
If included it should be exactly 6 characters long, in the hex triplet format with no preceding pound (#) sign.