It can be anything! An apex, subdomain, or even a URL.

Results for*.isitzen.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2014-10-06T03:48:53.148	2014-10-03T00:00:00	2015-10-16T23:59:59	*.isitzen.com	*.isitzen.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
2014-10-06T03:48:53.148	2014-10-03T00:00:00	2015-10-16T23:59:59	*.isitzen.com	*.isitzen.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
2013-10-20T12:28:11.254	2013-10-17T00:00:00	2014-10-17T23:59:59	*.isitzen.com	*.isitzen.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=PositiveSSL CA 2
2013-10-20T12:28:11.254	2013-10-17T00:00:00	2014-10-17T23:59:59	*.isitzen.com	*.isitzen.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=PositiveSSL CA 2