Website that allows user subdomains - what subdomains should

My website is going to allow users to choose their own subdomain. I’ve got quite a list going but want to see if there are any others out there that you think would be worth it…

Thanks in advance!

$banned_subdomains = array(
        'cname',
        'www',
        'test',
        'js',
        'css',
        'cache',
        'static',
        'img',
        'images',
        'mail',
        'ftp',
        'cpanel',
        'whm',
        'webmail',
        'webdisk',
        'ns',
        'ns1',
        'ns2',
        'ns3',
        'ns4',
        'ns5',
        'register',
        'pop',
        'pop3',
        'beta',
        'stage',
        'dev',
        'http',
        'https',
        'abuse',
        'admin',
        'donate',
        'store',
        'payment',
        'smtp'
        );