Host redirect using default redirection code
example.com -> about.example.com 301

example.com                   3600 IN A      127.0.0.1
_redirect.example.com         3600 IN TXT    "v=txtv0;type=host;to=https://about.example.com"

Host redirect using explicit 301 redirection code
www.example.com -> about.example.com 301

www.example.com               3600 IN CNAME  txtdirect.example.com.
_redirect.www.example.com     3600 IN TXT    "v=txtv0;type=host;code=301;to=https://about.example.com"

Host redirect using explicit 302 redirection code
www.example.com -> about.example.com 302

www.example.com               3600 IN CNAME  txtdirect.example.com.
_redirect.www.example.com     3600 IN TXT    "v=txtv0;type=host;code=302;to=https://about.example.com"

Host redirect using placeholder
example.com -> about.example.com 301

example.com                   3600 IN A      127.0.0.1
_redirect.example.com         3600 IN TXT    "v=txtv0;type=host;to=https://about.example.com{uri}"

Host redirect using multiple placeholders
placeholder.example.com/cat.png -> example.com/cat.png

placeholder.example.com              3600 IN CNAME  txtdirect.example.com.
_redirect.placeholder.example.com    3600 IN TXT    "v=txtv0;type=host;to=https://example.com/{path}{file}"