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

Results forspf1.web.com

Resolver

Location

TXT

Name	TTL	Value
spf1.web.com	1800	v=spf1 ip4:209.17.115.0/24 ip4:209.237.134.0/24 ip4:64.69.208.0/24 ip4:64.69.212.0/24 ip4:64.69.218.0/24 ip4:74.208.5.21/32 ip4:74.208.5.3/32 ip4:74.200.28.190 ip4:46.236.37.0/24 ip4:185.54.75.0/24 ip4:167.89.16.30 ip4:167.89.16.245 -all