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

Results for_sub1.broadcom.com

Resolver

Location

TXT

Name	TTL	Value
_sub1.broadcom.com	300	v=spf1 ip4:135.36.0.0/20 ip4:135.36.16.0/21 ip4:135.142.140.0/22 ip4:135.142.144.0/22 ip4:135.142.148.0/22 ip4:192.19.0.0/16 ip4:192.254.114.158 ~all