associated to a request and the log message happens at a time when the
Referer header has already been read from the client. If no output is
produced, the default behavior is to delete everything from the preceding
- space character to the next space character. This means the log line is
+ space character to the next space character. This means the format string is
implicitly divided into fields on non-whitespace to whitespace transitions.
If a format string item does not produce output, the whole field is
omitted. For example, if the remote address <code>%a</code> in the log