DNS records explained

A quick primer on the records you'll touch.

A record — points a name straight at an IP address.
CNAME — points a name at another name (an alias). Custom domains use the CNAME target we show you in the Domains tab.
TTL — how long resolvers cache the record. Lower it before a change so the change propagates faster.

You make these changes at your domain registrar or DNS host (Cloudflare, Namecheap, GoDaddy, etc.), not in MyBB.

A subdomain like forum.yoursite.com is the easiest setup — add the CNAME we give you and you're done.