10.5.37.  LogFormat

The LogFormat directive configures the format of the various Web server log files. The actual LogFormat used depends on the settings given in the CustomLog directive (refer to Section 10.5.38, “ CustomLog).
The following are the format options if the CustomLog directive is set to combined:
%h (remote host's IP address or hostname)
Lists the remote IP address of the requesting client. If HostnameLookups is set to on, the client hostname is recorded unless it is not available from DNS.
%l (rfc931)
Not used. A hyphen - appears in the log file for this field.
%u (authenticated user)
Lists the username of the user recorded if authentication was required. Usually, this is not used, so a hyphen - appears in the log file for this field.
%t (date)
Lists the date and time of the request.
%r (request string)
Lists the request string exactly as it came from the browser or client.
%s (status)
Lists the HTTP status code which was returned to the client host.
%b (bytes)
Lists the size of the document.
%\"%{Referer}i\" (referrer)
Lists the URL of the webpage which referred the client host to Web server.
%\"%{User-Agent}i\" (user-agent)
Lists the type of Web browser making the request.