NCSA Mosaic for Microsoft Windows User's Guide
Each type of server usually resides on a standard port on the host
machine. For example, HTTP servers generally reside on port 80 while
Gopher servers generally reside on port 70. When servers reside on
the standard ports, the port number need not be specified in the URL.
However, when a server resides on a non-standard port, the URL must
contain the port number. The port number immediately follows the machine
name and is separated from the machine name by a colon.
For example, if the HTTP server on the machine www at NCSA resided
on port 1234, you would use the following URL to retrieve the file
/pub/files/foobar.html:
http://www.ncsa.uiuc.edu:1234/pub/files/foobar.html
National Center for Supercomputing Applications / mosaic-win@ncsa.uiuc.edu