From http://awstats.sourceforge.net/docs/awstats_config.html#LogFormat:
# Enter here your log format (Must agree with your web server. See setup
# instructions in README.txt to know how to configure your web server to have
# the required log format).
# Possible values: 1,2,3,4 or "your_own_personalized_log_format"
# 1 - Apache or Lotus Notes/Domino native combined log format (NCSA combined/XLF/ELF log format)
# 2 - IIS or ISA format (IIS W3C log format). See FAQ-COM115 For ISA.
# 3 - Webstar native log format.
# 4 - Apache or Squid native common log format (NCSA common/CLF log format)
# With LogFormat=4, some features (browsers, os, keywords...) can't work.
# "your_own_personalized_log_format" = If your log is ftp, mail or other format,
# you must use following keys to define the log format string (See FAQ for
# ftp, mail or exotic web log format examples):
# %host Client hostname or IP address (or Sender host for mail log)
# %host_r Receiver hostname or IP address (for mail log)
# %lognamequot Authenticated login/user with format: "alex"
# %logname Authenticated login/user with format: alex
# %time1 Date and time with format: [dd/mon/yyyy:hh:mm:ss +0000] or [dd/mon/yyyy:hh:mm:ss]
# %time2 Date and time with format: yyyy-mm-dd hh-mm-ss
# %time3 Date and time with format: Mon dd hh:mm:ss or Mon dd hh:mm:ss yyyy
# %time4 Date and time with unix timestamp format: dddddddddd
# %methodurl Method and URL with format: "GET /index.html HTTP/x.x"
# %methodurlnoprot Method and URL with format: "GET /index.html"
# %method Method with format: GET
# %url URL only with format: /index.html
# %query Query string (used by URLWithQuery option)
# %code Return code status (with format for web log: 999)
# %bytesd Size of document in bytes
# %refererquot Referer page with format: "http://from.com/from.htm"
# %referer Referer page with format: http://from.com/from.htm
# %uaquot User agent with format: "Mozilla/4.0 (compatible, ...)"
# %ua User agent with format: Mozilla/4.0_(compatible...)
# %gzipin mod_gzip compression input bytes: In:XXX
# %gzipout mod_gzip compression output bytes & ratio: Out:YYY:ZZpct.
# %gzipratio mod_gzip compression ratio: ZZpct.
# %deflateratio mod_deflate compression ratio with format: (ZZ)
# %email EMail sender (for mail log)
# %email_r EMail receiver (for mail log)
# %virtualname Web sever virtual hostname. Use this tag when same log
# contains data of several virtual web servers. AWStats
# will discard records not in SiteDomain nor HostAliases
# %cluster If log file is provided from several computers (merged by
# logresolvemerge.pl), this tag define field of cluster id.
# %extraX Another field that you plan to use for building a
# personalized report with ExtraSection feature (See later).
# If your log format has some fields not included in this list, use
# %other Means another field
# %otherquot Means another not used double quoted field
#
# Examples for Apache combined logs (following two examples are equivalent):
# LogFormat = 1
# LogFormat = "%host %other %logname %time1 %methodurl %code %bytesd %refererquot %uaquot"
#
# Example for IIS:
# LogFormat = 2
#
LogFormat=1