Looks to me like the BF3 server Banner URL entry line in the control Panel Interface is missing.
This is the fixed edit options for startup.txt.
I can set the URL from Procon, but of course it does not persist (after restart) unless set in the startup.txt. And we are not given full edit access to that file, with no URL entry through the Rackage Control Panel.
Ah so it will show on battlelog rather than whilst joining. Would be nice to have a server blog and comments section (or at least a blog) maybe the comments section would be detrimental but maybe an option to disable it could be added. Maybe I should put that to EA