Merge branch 'selhorn-ipv6' into 'master'

Docs: IPv6 not currently supported for Pages

Closes #214438

See merge request gitlab-org/gitlab!29737

doc/user/project/pages/custom_domains_ssl_tls_certification/index.md

@@ -60,6 +60,11 @@ according to the type of domain you want to use with your Pages site:
 - [For subdomains](#for-subdomains), `subdomain.example.com`.
 - [For both](#for-both-root-and-subdomains).
 
+NOTE: **Note:**
+IPv6 is not currently configured for Pages on GitLab.com, but
+you can [configure IPv6 on self-managed instances].(../../../../administration/pages/index.md#advanced-configuration).
+Follow [this issue](https://gitlab.com/gitlab-org/gitlab/-/issues/214718) for details.
+
 ##### For root domains
 
 Root domains (`example.com`) require: