RFC2818 (the 'HTTP over TLS' specification) says that names may contain the wildcard character, which is considered to match any single domain name component or component fragment. E.g., *.a.com matches foo.a.com but not bar.foo.a.com. f*.com matches foo.com but not bar.com.<p>A careful reading of this wording does not seem to rule out the use of more than one wildcard, e.g. '*.*.com'. That's unfortunate. It likely depends on the particular browser's TLS implementation as to whether more than one wildcard in a name would be processed.