For more information on logging, refer to:
http://httpd.apache.org/docs/logs.html
"Apache HTTP Server: Log Files." Apache HTTP Server Project web site.
http://www.squid-cache.org/Doc/FAQ/FAQ-6.html
"Squid Log Files." Squid Proxy Cache web site.
http://www.w3.org/Daemon/User/Config/Logging.html#common-logfile-format
"Logging Control in W3C httpd."
http://www.w3.org/TR/WD-logfile.html
"Extended Log File Format."
http://www.ietf.org/rfc/rfc2227.txt
RFC 2227, "Simple Hit-Metering and Usage-Limiting for HTTP," by J. Mogul and P. Leach.