The AllowCONNECT directive specifies a list of
port numbers to which the proxy CONNECT method may
connect. Today's browsers use this method when a https
connection is requested and proxy tunneling over http is
in effect.
By default, only the default https port (443) and the default snews
port (563) are enabled. Use the AllowCONNECT directive
to overrride this default and allow connections to the listed ports
only.