It is easy to bash those complaints, but it does show that the IANA port assignments [1] do not work well for ports 1024-- in practice. You generally don't see

It is easy to bash those complaints, but it does show that the IANA port assignments [1] do not work well for ports 1024-- in practice. You generally don't see this kind of complaints for system ports (0--1023) because you need root for them in UNIXish systems and thus has a much higher bar for collision. If we were enfocing the same rule for ports 1024-- we should have overflown the IANA registry by now [2], but it will be absurd and we instead collectively chose to ignore the registry. It hardly makes a difference whether you have actually registered your port to the registry or not; you should prepare for a possibility that your use of that port collides with other's. [1] https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml https://www.iana.org/assignments/service-names-port-numbers/... [2] The actual rate is something like 3--50 new and updated entries per year.