Tutorial on wild cards?

Is there an up-to-date tutorial on learning how to add wild cards? The current FAQ post ends with the statement that this process is obsolete.

On the blacklist page, enter a domain (just a domain, no wildcard characters). Then, “add (wildcard)” and Pi-hole will convert the domain to a regex that will wildcard block that domain and all subdomains of that domain.

Thanks. I’ll try it. So that’s what he meant by “obsolete.”