It can be anything! An apex, subdomain, or even a URL.

Results forspf0.haulware.com

Resolver

Location

TXT

Name	TTL	Value
spf0.haulware.com	3600	v=spf1 ip4:54.240.0.0/18 ip4:69.169.224.0/20 ip4:23.249.208.0/20 ip4:76.223.176.0/20 ip4:54.240.64.0/19 ip4:54.240.96.0/19 ip4:76.223.128.0/19 ip4:216.221.160.0/19 ip4:206.55.144.0/20 ~all