Differences between the standard Web log format

> Hi,
> 
> We are looking at the use of various standard Web log formats.  The Common
> Log Format (CLF) is well documented and understood, but my understanding
> of the Extended Common Log Format (ECLF?)and Extended/Extensible Log File
> Format (XLF?) is not. 
> 
> Can you help.
> 
> Regards,
> 
> David Wales
> 
> Admiral Computing (UK)
> Tel : +44 1454 619700
> 
>