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

Results forsfdc.convio.com

Resolver

Location

TXT

Name	TTL	Value
sfdc.convio.com	600	spf2.0/pra +ip4:204.14.232.68/30 +ip4:204.14.234.68/30 +ip4:63.146.199.0/24 ~all
sfdc.convio.com	600	v=spf1 +ip4:204.14.232.68/30 +ip4:204.14.234.68/30 +ip4:63.146.199.0/24 ~all