gnu-social/docs/user/src/install/dns.md

Configuring DNS

In order for your GNU social node to be accessible with your chosen hostname, you can create an A or AAAA DNS record, with your server's fixed IP v4 or v6 respectively in your DNS provider (normally, your domain registrar); the A record doesn't need to be at the root of your domain, meaning it's name can be a subdomain. For dynamic IPs, create a CNAME record pointing to the hostname you created with your chosen Dynamic DNS host. A CNAME cannot normally be created for a domain root, so you must use a subdomain. Note that some DNS providers provide 'CNAME flattening', in which case you can use your root domain.