DNS Lookup Examples · Example 8 of 13 in Record Types
CAA Records: Allowed Certificate Authorities
The CAA record of google.com: which certificate authority may issue certificates for the domain.
Asks for the CAA records of google.com.
A CAA record says which certificate authorities may issue SSL/TLS certificates for a domain. The single value 0 issue "pki.goog" allows only Google's own CA.