Update content/docs/capabilities/custom-domains.mdx

Co-authored-by: Kenneth Jenkins <[email protected]>

Author: ZPain8464

content/docs/capabilities/custom-domains.mdx

@@ -26,7 +26,7 @@ See the Clusters Concepts page for more information about clusters in Pomerium Z
 
 ## Custom Domains
 
-In Pomerium Zero, a valid **Custom Domain** is a fully qualified domain name (FQDN) where the domain owner can demonstrate control over the domain through DNS validation.
+In Pomerium Zero, a **Custom Domain** is a wildcard sub-domain you can use for Pomerium routes. After a one-time setup with your DNS provider, Pomerium will automatically provision and renew a TLS certificate for this sub-domain.
 
 After you successfully add a custom domain to your cluster, Pomerium will automatically issue and renew X.509 wildcard certificates on behalf of the domain to secure the connection over TLS.