Re: Reserved Ports and non-superuser Daemons

[rohnskii () gmail com]

those ports are actually called "Well Known" ports by IANA.

(snip>
WELL KNOWN PORT NUMBERS

The Well Known Ports are assigned by the IANA and on most systems can
only be used by system (or root) processes or by programs executed by
privileged users.

Ports are used in the TCP [RFC793] to name the ends of logical
connections which carry long term conversations.  For the purpose of
providing services to unknown callers, a service contact port is
defined.  This list specifies the port used by the server process as
its contact port.  The contact port is sometimes called the
"well-known port".

To the extent possible, these same port assignments are used with the
UDP [RFC768].

The range for assigned ports managed by the IANA is 0-1023.
(/snip>

Check this link for more details:
http://www.iana.org/assignments/port-numbers