Do53
DoH53 stands for DNS over Plain Text. The good old unencrypted port 53. Either UDP or TCP.
The plain DNS port was or still is used in my systems and devices. If you care about security you should not use this port anymore on your devices. Or if you do use, then it should at least only be in your local trusted network between your clients and your local dns resolver.
The local resolver should then use one of the encrypted protocols to talk to an external DNS server.
If you need to do a quick dns lookup for some troubleshooting, then using this port might also be a good start. Just to check the basics.
dig
# udp
dig a heise.de @dns.loopx.org
# tcp
dig a heise.de @dns.loopx.org +tcp
q
# udp
q a heise.de @plain://dns.loopx.org --stats
# tcp
q a heise.de @tcp://dns.loopx.org --stats