[squid-users] What's with "Safe_ports"?

I'm a little unclear on what the lines below, as seen in the default
squid.conf, are supposed to do.

  acl Safe_ports port 80 # http
  acl Safe_ports port 21 # ftp
  acl Safe_ports port 443 563 # https, snews
  acl Safe_ports port 70 # gopher
  acl Safe_ports port 210 # wais
  acl Safe_ports port 1025-65535 # unregistered ports
  acl Safe_ports port 280 # http-mgmt
  acl Safe_ports port 488 # gss-http
  acl Safe_ports port 591 # filemaker
  acl Safe_ports port 777 # multiling http

The first line is understandable; we're caching HTTP traffic, therefore
port 80 must be accessible. But what's the story on the remaining lines?
Why is SHTTP, which is unsupported by Squid, considered safe? Why is
FileMaker, of all things, considered safe for use by Squid?

Given that all I care about is HTTP traffic, is there any reason I
shouldn't delete all but the first of these lines?

Thank you.
Received on Mon May 28 2001 - 22:06:14 MDT