By default, Apache logs the IP address of each requesting client. If you'dprefer something a bit friendlier, you can have Apache log the host name ofeach client, rather than the IP address. This behaviour is controlledthrough the HostNameLookups directive - turn it on to enable name lookups.
Be warned, however, that turning this feature on is likely to slow down theWeb server, since it will have to perform a lookup for each distinctvisitor to your Web page.
And finally, you can specify the type and severity of errors that are to belogged to the error log with the LogLevel directive. A number of errorlevels are available, ranging from "emerg" and "crit" (for severe errors)to "info" and "debug" (less-critical information).
This directive comes in particularly handy when you roll your own Apacheserver and things aren't working quite as advertised.