[pmwiki-users] zlib.output_compression_level

[JB]

In the cookbook

  http://www.pmwiki.org/wiki/Cookbook/OutputCompression

There is sample code

   if ( !@ini_set('zlib.output_compression',TRUE) &&
        !@ini_set('zlib.output_compression_level',2))
          ob_start('ob_gzhandler');

Why did the author set zlib.output_compression_level' to 2 when 
the default value is 6?